Arterial device, system and method for removing embolic debris

ABSTRACT

An arterial device, system and method are provided for use with a patient undergoing a cardiac procedure. The system is configured for enabling one or more arterial devices to be accommodated in the aorta of the patient in use of the system, and a perfusion lumen arrangement provides therethrough a target perfusion flow into the aorta having a target perfusion flow rate that is significantly greater than a nominal perfusion flow rate, by an excess perfusion flow rate. A suction lumen arrangement provides therethrough a suction flow out of the aorta at a suction flow rate. The target perfusion flow rate and the suction flow rate may be concurrently and selectively controlled to cause embolic debris that may be present in the aorta to be diverted to the suction inlet, while providing the nominal flow rate to the body circulation of the patient.

FIELD OF THE INVENTION

This invention relates to arterial devices, systems and methods,particularly associated with performing cardiopulmonary bypass or thelike, and/or associated with the removal of embolic debris.

BACKGROUND OF THE INVENTION

It is known that patients undergoing cardiopulmonary bypass (CPB) duringcardiac surgery (usually open heart surgery (in which the heart isopened with a cutting instrument), but sometimes also closed heartsurgery (in which the heart is not opened with a cutting instrument))run a risk of neurologic and neuropsychologic deficit, which are thoughtto be caused or exacerbated by some types of embolic debris that areknown to be released into the aortic arch during cardiac surgery or CPBand are introduced into the cerebral circulation.

Various devices, systems and methods are known for use in CPB. Forexample, U.S. Pat. No. 6,689,149 discloses a balloon occlusion devicefor aspirating embolic material from a blood vessel, such as from theaorta during cardiac surgery. The device includes an arterial cannulahaving a proximal end adapted to receive blood from a bypass-oxygenatormachine, a distal end adapted to enter an artery, and a blood flow lumenextending between the proximal end and an outlet on the distal end. Thecannula has an aspiration port proximate to the outlet, whichcommunicates with an aspiration lumen. The cannula also includes aninflatable balloon attached to the cannula between the outlet and theaspiration port and capable of assuming an inflated condition foroccluding a blood vessel. To use the device, the distal end of thecannula is introduced into a blood vessel, such as the aorta, the outletis oriented downstream for delivering blood, and the balloon is inflatedto occlude the vessel. In operation, fluid may then be flushed into andaspirated out through the aspiration port to remove loose embolicmaterial from the vessel upstream of the balloon. Optionally, the devicemay include a second deployable balloon for further occluding the vesselat a second location.

U.S. Pat. No. 6,726,651 discloses methods, systems and devices forperforming cardipulmonary bypass (CPB), cardioplegic arrest, suction offluid from the aorta to remove embolic or other fluid from the generalcirculation and the selective segmentation of the arterial system toperform differential perfusion eliminating hypoperfusion. An aorticcatheter having an arch lumen which extends at least in part along thelength of the catheter shaft has a proximal opening coupled to a CPBmachine and a distal arch opening. A corporeal lumen extends at least inpart along the length of the catheter shaft and has a proximal openingcoupled to a CPB machine and a distal corporeal opening. A suction lumenextends at least in part along the length of the catheter shaft and hasa proximal suction opening coupled to a suction source and a distalsuction opening residing in the aortic lumen of a patient.

U.S. Pat. No. 5,697,905 discloses a method and apparatus used duringcardiac surgery for reducing release of embolized air and particulatematter into general body circulatory system are disclosed. The methoduses a catheter apparatus having an inflation lumen, an occlusiveballoon, a suction lumen and a perfusion lumen. The catheter is insertedor navigated to into an aortic root and positioned so a suction openingcommunicates upstream of the aortic root and a perfusion openingcommunicates downstream of the suction opening. The patient's heart isstopped and the occlusive balloon is inflated to occlude the aorta.Cardiac surgery is performed and when the patient's heart is restartedthe blood pumped by the heart during its first few contractions issuctioned through the suction opening.

U.S. Pat. No. 7,470,363 discloses a number of ultrasonic devices forpreventing microbubbles and/or microparticles from reaching the brainduring a percutaneous cardiological intervention (PCI) or cardiacsurgery.

U.S. Pat. No. 5,425,724 discloses an aortic cannula having one tube forblood perfusion, and another tube for monitoring arterial pressure.

SUMMARY OF THE INVENTION

Embolic debris herein refers to any emboli or particles, including forexample mircroparticles or microbubbles, that may be released as aresult of the use of an artificial heart-lung machine (bypass-oxygenatormachine), and/or due to clamping and/or manipulation of the aorta or theheart during CPB, for example. Embolic debris herein refers also to airbubbles, for example, as may exist in the heart ventricles prior tounclamping, and which are often released to the aorta after unclamping.

According to a first aspect of the invention there is provided anarterial system, comprising an arterial flow exchange system and acontroller, for use with a patient having an aorta and a body bloodcirculation system, wherein:

-   -   said arterial flow exchange system comprises a distal portion        arrangement configured for being accommodated in the aorta of        the patient in use of the arterial flow exchange system, said        distal portion arrangement comprising:        -   a perfusion lumen arrangement having at least one perfusion            outlet and connectable to at least one perfusion source,            said perfusion lumen arrangement being configured for            providing therethrough a target perfusion flow into the            aorta (via said at least one perfusion outlet) having a            target perfusion flow rate that is greater than a nominal            perfusion flow rate by an excess perfusion flow rate,            wherein said nominal perfusion flow is sufficient for            providing adequate fluid flow to the body blood circulation            system of the patient;        -   and        -   a suction lumen arrangement having at least one suction            inlet and connectable to a suction source, said suction            lumen arrangement being configured for providing a suction            flow out of the aorta (via said at least one suction inlet),            said suction flow having a suction flow rate;        -   said distal portion being configured for providing fluid            communication between at least one said perfusion outlet and            at least one said suction inlet within the aorta via an            outside of said distal portion, in use of the arterial            system;    -   said controller being configured, in use of the arterial system,        for:        -   selectively controllably providing a target perfusion flow            into the aorta at said target perfusion flow rate;        -   selectively controllably providing a suction flow out of the            aorta at said suction flow rate; and        -   selectively controlling said target perfusion flow rate and            said suction flow rate concurrently to cause embolic debris            that may be present in the aorta to be diverted to said at            least one suction inlet.

The arterial system according to this aspect of the invention maycomprise any one of the following features, or more than one of thefollowing features in any combination or permutation:

-   -   (A) wherein said controller is configured for selectively        controlling said target perfusion flow rate and said suction        flow rate to establish a recirculation flowfield between at        least one said perfusion outlet and at least one said suction        inlet within the aorta to cause the embolic debris that may be        present in the aorta to be diverted to the respective at least        one said suction inlet.    -   (B) wherein said controller is configured for selectively        matching said suction flow rate with said excess perfusion flow        rate according to a desired matching level, defined as a        percentage of said suction flow rate with respect to said excess        perfusion flow rate. For example, said matching level may be        about 100%, or may be greater than 100%. For example, said        matching level may be in a range between about 50% and about        100%.    -   (C) wherein said target perfusion flow rate is a first        proportion of said nominal perfusion flow rate, wherein said        first proportion is not less than about 110% of said nominal        perfusion flow rate. For example, said first proportion may be        between about 110% and about 150% of said nominal perfusion flow        rate, or, for example, said first proportion may be between        about 115% and about 160% of said nominal perfusion flow rate,        or, for example, said first proportion may be between about 120%        and about 150% of said nominal perfusion flow rate, or, for        example, said first proportion may be between about 120% and        about 170% of said nominal perfusion flow rate.    -   (D) wherein said suction flow rate is a second proportion of a        said nominal perfusion flow rate, wherein said second proportion        is not less than about 10% of said nominal perfusion flow rate.        For example, said second proportion may be between about 10% and        about 50% of said nominal perfusion flow rate, or, for example,        said second proportion may be between about 15% and about 60% of        said nominal perfusion flow rate, or, for example, said second        proportion may be between about 20% and about 50% of said        nominal perfusion flow rate, or, for example, said second        proportion may be between about 20% and about 70% of said        nominal perfusion flow rate.    -   (E) wherein said arterial flow exchange system is configured for        operating in the aorta to provide said excess perfusion flow        rate and to provide said suction flow rate in the absence of        establishing occlusion of the aorta at least in a region of the        aorta corresponding to a part of the arterial flow exchange        system extending between said at least one suction inlet and        said at least one perfusion outlet.    -   (F) wherein said device has an absence of an occlusion        arrangement that is otherwise configured for providing occlusion        of the aorta in operation of said system, at least between said        at least one suction inlet and said at least one perfusion        outlet.    -   (G) wherein said arterial system is configured for providing at        least one said suction inlet within the ascending aorta of the        patient in operation of the arterial system.    -   (H) wherein said arterial flow exchange system is configured in        operation of the arterial system for causing at least a majority        of embolic debris that may be present in the aorta to be        diverted to said at least one suction inlet at least from        upstream of said at least one suction inlet.    -   (I) wherein said controller is configured for providing said        target perfusion flow rate wherein a corresponding target        perfusion flow velocity is below a threshold value for avoiding        or minimizing damage to blood cells, and/or, wherein said        controller is configured for providing said suction flow rate at        a corresponding suction flow velocity that is below a threshold        value for avoiding or minimizing damage to blood cells; and/or        wherein said perfusion lumen arrangement is configured for        providing said target perfusion flow rate wherein a        corresponding target perfusion flow velocity is below a        threshold value for avoiding or minimizing damage to blood        cells, and/or, wherein said suction lumen arrangement is        configured for providing said suction flow rate at a        corresponding suction flow velocity that is below a threshold        value for avoiding or minimizing damage to blood cells.    -   (J) wherein said distal portion arrangement comprises at least        one additional suction outlet port configured for de-airing the        aorta by facilitating removing of said embolic debris in the        form of air bubbles.

In at least a first form of the arterial system according to the firstaspect of the invention, said arterial flow exchange system (as definedabove, optionally comprising any one of features (A) to (J), or morethan one of features (A) to (J) in any combination or permutation), maybe embodied (in particular, may be integrally embodied) in an arterialdevice, and said distal portion arrangement constitutes a distal portionof said arterial device and is configured for being accommodated intothe aorta.

In at least some embodiments according to the said first form of thearterial system, said arterial device is in the form of an aorticcannula, wherein said distal portion is configured for being introducedinto the aorta via a wall of the ascending aorta. In at least one suchembodiment, said distal portion comprises a curved portion and a distalend, wherein said distal end comprises said at least one perfusionoutlet, and wherein said curved portion comprises said at least onesuction inlet. In operation said at least one perfusion outlet is facingin a generally downstream direction along the aorta and said at leastone suction inlet is facing in a generally upstream direction along theaorta. Optionally, said perfusion lumen arrangement comprises a firstlumen, wherein said suction lumen arrangement comprises a second lumen,and wherein said first lumen and said second lumen are integrally formedin said distal portion. The first lumen may have a first flowcross-section and said second lumen may have a second flowcross-section, wherein a cross section ratio between said first flowcross-section and said second flow cross-section is not less than about1.10. For example, said cross section ratio may be between about 1.10and about 10.0. In at least some embodiments, said distal portioncomprises one said perfusion outlet and one said suction inlet.

In at least some other embodiments according to the said first form ofthe arterial system, said arterial device is in the form of an aorticcatheter, wherein said distal portion is configured for being introducedinto the aorta via an entry point at a location downstream of thedescending aorta, the distal portion being further configured for beingnavigated upstream to the ascending aorta. In at least one suchembodiment, said distal portion comprises a distal end and an elongateportion extending proximally from said distal end, wherein said distalend comprises said at least one perfusion outlet, and wherein saidelongate portion comprises said at least one suction inlet. In operationsaid at least one perfusion outlet is downstream of said at least onesuction inlet with respect to antegrade flow in the aorta. In operation,said at least one suction inlet is facing in a generally upstreamdirection along the aorta in operation of the arterial system.Optionally, said perfusion lumen arrangement comprises a first lumen andsaid suction lumen arrangement comprises a second lumen, and whereinsaid first lumen and said second lumen are integrally formed coaxiallyin said distal portion. Said first lumen may have a first flowcross-section and said second lumen may have a second flowcross-section, wherein a cross section ratio between said first flowcross-section and said second flow cross-section is not less than about1.10. For example, said cross section ratio is between about 1.10 andabout 10. In some such embodiments, said distal portion comprises aplurality of said perfusion outlets and one said suction inlet; in othersuch embodiments, said distal portion comprises a plurality of saidperfusion outlets and a plurality of said suction inlets; optionally ineither case, said plurality of perfusion outlet ports may comprise atleast a first group of said perfusion outlet ports and a second group ofsaid perfusion outlet ports, wherein said second group is locatedproximally of said first group, and wherein said first group is locatedwithin the ascending aorta or aortic arch in operation of the arterialsystem.

In at least a second form of the arterial system, said arterial flowexchange system (as defined above, optionally comprising any one offeatures (A) to (J), or more than one of features (A) to (J) in anycombination or permutation), comprises a first arterial device and asecond arterial device separate from said first arterial device, andsaid distal portion arrangement comprises a distal portion of said firstarterial device and a distal portion of said second device, wherein saidfirst arterial device and said second arterial device are configured forbeing independently accommodated into the aorta, wherein said perfusionlumen arrangement comprises at least a first perfusion lumen comprisedin said first arterial device, and at least one second perfusion lumencomprised in said second arterial device, and wherein said suction lumenarrangement comprises at least one suction lumen comprised in saidsecond arterial device.

In at least some embodiments following said second form of the arterialsystem said first arterial device is configured for providing saidnominal perfusion flow rate via said at least one first perfusion lumenand at least one respective said perfusion outlet comprised in saidfirst arterial device, wherein said second arterial device is configuredfor providing said excess perfusion flow rate via said at least onesecond perfusion lumen and at least one respective said perfusion outletcomprised in said second arterial device, and wherein said secondarterial device is further configured to provide said suction flow ratevia said suction lumen and at least one said suction inlet comprised insaid second arterial device. In at least some such embodiments, saidsecond arterial device is in the form of an aortic cannula, wherein saidsecond distal portion is configured for being introduced into the aortavia a wall of the ascending aorta. Additionally or alternatively, (i)said first arterial device is in the form of an aortic cannula, whereinsaid first distal portion is configured for being introduced into theaorta via a wall of the aorta proximal to said second arterial device,or (ii) said first arterial device is in the form of an aortic catheter,wherein said first distal portion is configured for being introducedinto the aorta via an entry point at a location downstream of thedescending aorta, the first distal portion being further configured forbeing navigated upstream to the ascending aorta to a position proximalto said second arterial device.

According to the first aspect of the invention, the arterial system, asdefined above, optionally comprising any one of features (A) to (J), ormore than one of features (A) to (J) in any combination or permutation,and/or according to the aforementioned first form of the arterial systemor according to the aforementioned second form of the arterial system,may be further configured according to any one of the followingfeatures, or according to more than one of the following features in anycombination or permutation:

-   -   (K) wherein said nominal perfusion flow rate is in the range        between about 3 liters per minute to about 5 liters per minute;    -   (L) wherein said target flow rate is in the range between about        3.3 liters per minute to about 7.5 liters per minute;    -   (M) wherein said excess perfusion flow rate is in the range        between about 0.3 liters per minute to about 2.5 liters per        minute;    -   (N) wherein said suction flow rate is greater than 0.5 liters        per minute;    -   (O) wherein said suction flow rate is greater than 0.75 liters        per minute; wherein said suction flow rate is greater than 1        liter per minute;    -   (P) wherein said suction flow rate is greater than 1.25 liters        per minute;    -   (Q) wherein said suction flow rate is in the range between about        0.5 liters per minute to about 2.0 liters per minute;    -   (R) wherein said suction flow rate is in the range between about        0.5 liters per minute to about 2.5 liters per minute;    -   (S) wherein said suction flow rate is in the range between about        0.75 liters per minute to about 2.5 liters per minute.

In operation of the arterial system according to the first aspect of theinvention, said perfusion lumen arrangement is connected to said atleast one perfusion source, and said suction lumen arrangement isconnected to said suction source.

According to the first aspect of the invention there is also provided anarterial device, for use with a patient having an aorta and a body bloodcirculation system, the arterial device comprising a distal portionarrangement configured for being accommodated in the aorta of thepatient in use of the arterial device, said distal portion arrangementcomprising:

-   -   a perfusion lumen arrangement having at least one perfusion        outlet and connectable to at least one perfusion source, said        perfusion lumen arrangement being configured for providing        therethrough a target perfusion flow into the aorta (via said at        least one perfusion outlet) having a target perfusion flow rate        that is greater than a nominal perfusion flow rate by an excess        perfusion flow rate, wherein said nominal perfusion flow is        sufficient for providing adequate fluid flow to the body blood        circulation system of the patient;    -   and    -   a suction lumen arrangement having at least one suction inlet        and connectable to a suction source, said suction lumen        arrangement being configured for providing a suction flow out of        the aorta (via said at least one suction inlet), said suction        flow having a suction flow rate;    -   said distal portion being configured for providing fluid        communication between at least one said perfusion outlet and at        least one said suction inlet within the aorta via an outside of        said distal portion, in use of the arterial device;    -   wherein the arterial device is configured for enabling said        target perfusion flow rate and said suction flow rate to be        concurrently and selectively controlled to cause embolic debris        that may be present in the aorta to be diverted to said at least        one suction inlet.

The arterial device according to this aspect of the invention and asdefined above may comprise any one of the following features, or morethan one of the following features in any combination or permutation:

-   -   (A1) wherein said arterial device is configured for enabling        selectively matching said suction flow rate with said excess        perfusion flow rate according to a desired matching level,        defined as a percentage of said suction flow rate with respect        to said excess perfusion flow rate. For example, said matching        level may be about 100%, or may be greater than 100%. For        example, said matching level may be in a range between about 50%        and about 100%.

(B1) wherein said target perfusion flow rate is a first proportion ofsaid nominal perfusion flow rate, wherein said first proportion is notless than about 110% of said nominal perfusion flow rate. For example,said first proportion may be between about 110% and about 150% of saidnominal perfusion flow rate, or, for example, said first proportion maybe between about 115% and about 160% of said nominal perfusion flowrate, or, for example, said first proportion may be between about 120%and about 150% of said nominal perfusion flow rate, or, for example,said first proportion may be between about 120% and about 170% of saidnominal perfusion flow rate.

-   -   (C1) wherein said suction flow rate is a second proportion of a        said nominal perfusion flow rate, wherein said second proportion        is not less than about 10% of said nominal perfusion flow rate.        For example, said second proportion may be between about 10% and        about 50% of said nominal perfusion flow rate, or, for example,        said second proportion may be between about 15% and about 60% of        said nominal perfusion flow rate, or, for example, said second        proportion may be between about 20% and about 50% of said        nominal perfusion flow rate, or, for example, said second        proportion may be between about 20% and about 70% of said        nominal perfusion flow rate.    -   (D1) wherein said arterial device is configured for operating in        the aorta to provide said excess perfusion flow rate and to        provide said suction flow rate in the absence of establishing        occlusion of the aorta at least in a region of the aorta        corresponding to a part of the arterial device extending between        said at least one suction inlet and said at least one perfusion        outlet.    -   (E1) wherein said device having an absence of an occlusion        arrangement that is otherwise configured for providing occlusion        of the aorta in operation of said arterial device, at least        between said at least one suction inlet and said at least one        perfusion outlet.    -   (F1) wherein said arterial device is configured for providing at        least one said suction inlet within the ascending aorta of the        patient in operation of the arterial device.    -   (G1) wherein said flow exchange arterial device is configured in        operation of the arterial device for causing at least a majority        of embolic debris that may be present in the aorta to be        diverted to said at least one suction inlet at least from        upstream of said at least one suction inlet.    -   (H1) wherein said arterial device is configured for providing        said target perfusion flow rate wherein a corresponding target        perfusion flow velocity is below a threshold value for avoiding        or minimizing damage to blood cells, and/or wherein said        arterial device is configured for providing said suction flow        rate at a corresponding suction flow velocity that is below a        threshold value for avoiding or minimizing damage to blood        cells; and/or wherein said perfusion lumen arrangement is        configured for providing said target perfusion flow rate wherein        a corresponding target perfusion flow velocity is below a        threshold value for avoiding or minimizing damage to blood        cells, and/or, wherein said suction lumen arrangement is        configured for providing said suction flow rate at a        corresponding suction flow velocity that is below a threshold        value for avoiding or minimizing damage to blood cells.    -   (I1) wherein said distal portion arrangement comprises at least        one additional suction outlet port configured for de-airing the        aorta by facilitating removing of said embolic debris in the        form of air bubbles.

In at least a first group of embodiments, said arterial device asdefined above, optionally comprising any one of features (A1) to (I1),or more than one of features (A1) to (I1) in any combination orpermutation, is in the form of an aortic cannula, wherein said distalportion is configured for being introduced into the aorta via a wall ofthe ascending aorta. In at least one such embodiment of said firstgroup, said distal portion comprises a curved portion and a distal end,wherein said distal end comprises said at least one perfusion outlet,and wherein said curved portion comprises said at least one suctioninlet. In operation said at least one perfusion outlet is facing in agenerally downstream direction along the aorta and said at least onesuction inlet is facing in a generally upstream direction along theaorta. Additionally or alternatively, said perfusion lumen arrangementcomprises a first lumen, wherein said suction lumen arrangementcomprises a second lumen, and wherein said first lumen and said secondlumen are integrally formed in said distal portion. The first lumen mayhave a first flow cross-section and said second lumen may have a secondflow cross-section, wherein a cross section ratio between said firstflow cross-section and said second flow cross-section is not less thanabout 1.10. For example, said cross section ratio is between about 1.10and about 10.0. In at least some such embodiments of said first group,said distal portion comprises one said perfusion outlet and one saidsuction inlet.

In at least a second group of embodiments, said arterial device asdefined above, optionally comprising any one of features (A1) to (I1),or more than one of features (A1) to (I1) in any combination orpermutation, is in the form of an aortic catheter, wherein said distalportion is configured for being introduced into the aorta via an entrypoint at a location downstream of the descending aorta, the distalportion being further configured for being navigated upstream to theascending aorta. In at least some such embodiments of said second group,said distal portion comprises a distal end and an elongate portionextending proximally from said distal end, wherein said distal endcomprises said at least one perfusion outlet, and wherein said elongateportion comprises said at least one suction inlet. In operation said atleast one perfusion outlet is downstream of said at least one suctioninlet with respect to antegrade flow in the aorta. In at least some suchembodiments of said second group of embodiments, said at least onesuction inlet is facing in a generally upstream direction along theaorta in operation of the arterial device. Optionally, said perfusionlumen arrangement comprises a first lumen and said suction lumenarrangement comprises a second lumen, and wherein said first lumen andsaid second lumen are integrally formed coaxially in said distalportion. Said first lumen may have a first flow cross-section and saidsecond lumen may have a second flow cross-section, wherein a crosssection ratio between said first flow cross-section and said second flowcross-section is not less than about 1.10. For example, said crosssection ratio is between about 1.10 and about 10. In some suchembodiments, said distal portion comprises a plurality of said perfusionoutlets and one said suction inlet; in other such embodiments, saiddistal portion comprises a plurality of said perfusion outlets and aplurality of said suction inlets; optionally in either case, saidplurality of perfusion outlet ports comprises at least a first group ofsaid perfusion outlet ports and a second group of said perfusion outletports, wherein said second group of said perfusion outlet ports islocated proximally of said first group of said perfusion outlet ports,and wherein said first group of said perfusion outlet ports is locatedwithin the ascending aorta or aortic arch in operation of the arterialdevice.

According to the first aspect of the invention, the arterial device, asdefined above, optionally comprising any one of features (A1) to (I1),or more than one of features (A1) to (I1) in any combination orpermutation, and/or according to the aforementioned first group ofembodiments of the arterial device or according to the aforementionedsecond group of embodiments of the arterial device, may be furtherconfigured according to any one of the following features, or accordingto more than one of the following features in any combination orpermutation:

-   -   (J1) wherein said nominal perfusion flow rate is in the range        between about 3 liters per minute to about 5 liters per minute;    -   (K1) wherein said target flow rate is in the range between about        3.3 liters per minute to about 7.5 liters per minute;    -   (L1) wherein said excess perfusion flow rate is in the range        between about 0.3 liters per minute to about 2.5 liters per        minute;    -   (M1) wherein said suction flow rate is greater than 0.5 liters        per minute;    -   (N1) wherein said suction flow rate is greater than 0.75 liters        per minute; wherein said suction flow rate is greater than 1        liter per minute;    -   (O1) wherein said suction flow rate is greater than 1.25 liters        per minute;    -   (P1) wherein said suction flow rate is in the range between        about 0.5 liters per minute to about 2.0 liters per minute;    -   (Q1) wherein said suction flow rate is in the range between        about 0.5 liters per minute to about 2.5 liters per minute;    -   (R1) wherein said suction flow rate is in the range between        about 0.75 liters per minute to about 2.5 liters per minute.

According to the first aspect of the invention there is also provided amethod for removing embolic debris from an aorta of a patient having abody blood circulation system, comprising:

-   -   (a) providing an arterial flow exchange system comprising a        distal portion arrangement configured for being accommodated in        the aorta of the patient in use of the arterial flow exchange        system, said distal portion arrangement comprising:        -   a perfusion lumen arrangement having at least one perfusion            outlet and connectable to at least one perfusion source,            said perfusion lumen arrangement being configured for            providing therethrough a target perfusion flow into the            aorta having a target perfusion flow rate that is greater            than a nominal perfusion flow rate by an excess perfusion            flow rate, wherein said nominal perfusion flow is sufficient            for providing adequate fluid flow to the body blood            circulation system of the patient;        -   and        -   a suction lumen arrangement having at least one suction            inlet and connectable to a suction source, said suction            lumen arrangement being configured for providing a suction            flow out of the aorta, said suction flow having a suction            flow rate;        -   said distal portion being configured for providing fluid            communication between at least one said perfusion outlet and            at least one said suction inlet within the aorta via an            outside of said distal portion, in use of the arterial flow            exchange system;    -   (b) accommodating said distal portion arrangement in the aorta        of the patient so that at least one said suction inlet port is        accommodated in the ascending aorta of the patient;    -   (c) controllably providing a target perfusion flow into the        aorta at said target perfusion flow rate;    -   (d) controllably providing a suction flow out of the aorta at        said suction flow rate; and    -   (e) selectively controlling said target perfusion flow rate and        said suction flow rate to cause embolic debris that may be        present in the aorta to be diverted to said at least one suction        inlet.

Optionally, step (e) comprises selectively controlling said targetperfusion flow rate and said suction flow rate to establish arecirculation flowfield between at least one said perfusion outlet andat least one said suction inlet within the aorta to cause the embolicdebris that may be present in the aorta to be diverted to the respectiveat least one said suction inlet.

Additionally or alternatively, step (b) comprises accommodating saiddistal portion arrangement in the aorta of the patient so that at leastone said perfusion outlet port is accommodated in the ascending aorta ofthe patient.

Additionally or alternatively, step (b) comprises accommodating saiddistal portion arrangement in the aorta of the patient so that at leastone said perfusion outlet port is accommodated in the aortic arch of thepatient.

Additionally or alternatively, step (e) comprises selectively matchingsaid suction flow rate with said excess perfusion flow rate according toa desired matching level, defined as a percentage of said suction flowrate with respect to said excess perfusion flow rate. For example, saidmatching level is about 100%, or above 100%. For example, said matchinglevel is between about 50% and about 100%.

Additionally or alternatively, said target perfusion flow rate is afirst proportion of said nominal perfusion flow rate, wherein said firstproportion is not less than about 110% of said nominal perfusion flowrate.

Additionally or alternatively, said target perfusion flow rate is afirst proportion of said nominal perfusion flow rate, wherein said firstproportion is not less than about 110% of said nominal perfusion flowrate. For example, said first proportion may be between about 110% andabout 150% of said nominal perfusion flow rate, or, for example, saidfirst proportion may be between about 115% and about 160% of saidnominal perfusion flow rate, or, for example, said first proportion maybe between about 120% and about 150% of said nominal perfusion flowrate, or, for example, said first proportion may be between about 120%and about 170% of said nominal perfusion flow rate.

Additionally or alternatively, said suction flow rate is a secondproportion of a said nominal perfusion flow rate, wherein said secondproportion is not less than about 10% of said nominal perfusion flowrate. For example, said second proportion may be between about 10% andabout 50% of said nominal perfusion flow rate, or, for example, saidsecond proportion may be between about 15% and about 60% of said nominalperfusion flow rate, or, for example, said second proportion may bebetween about 20% and about 50% of said nominal perfusion flow rate, or,for example, said second proportion may be between about 20% and about70% of said nominal perfusion flow rate.

Additionally or alternatively, said, at least steps (b) to (e) areconducted in the absence of establishing occlusion of the aorta at leastin a region of the aorta corresponding to a part of the device extendingbetween said at least one suction inlet and said at least one perfusionoutlet.

Additionally or alternatively, said device has an absence of anocclusion arrangement that is otherwise configured for providingocclusion of the aorta in operation of said device, at least betweensaid at least one suction inlet and said at least one perfusion outlet.

Additionally or alternatively, in step (e) at least a majority ofembolic debris that may be present in the aorta are caused to bediverted to said at least one suction inlet at least from upstream ofsaid at least one suction inlet.

Additionally or alternatively, said target perfusion flow rate isprovided having a corresponding target perfusion flow velocity that isbelow a threshold value for avoiding or minimizing damage to bloodcells, and/or said suction flow rate is provided at a correspondingsuction flow velocity that is below a threshold value for avoiding orminimizing damage to blood cells.

Additionally or alternatively, said distal portion arrangement comprisesat least one additional suction outlet port configured for de-airing theaorta, and further comprising the step of removing said embolic debrisin the form of air bubbles.

In at least a first form of carrying out the method, said arterial flowexchange system is embodied in an arterial device, and said distalportion arrangement constitutes a distal portion of said arterial deviceand configured for being accommodated into the aorta.

For example, said arterial device is in the form of an aortic cannula,and in step (b) said distal portion is introduced into the aorta via awall of the ascending aorta.

Alternatively, said arterial device is in the form of an aorticcatheter, and in step (b) said distal portion is introduced into theaorta via an entry point at a location downstream of the descendingaorta, and said distal portion is navigated upstream to the ascendingaorta. For example, said entry point is provided in a femoral artery oran iliac artery of the patient.

Additionally or alternatively, said perfusion lumen arrangementcomprises a perfusion lumen having a first flow cross-section, and saidsuction lumen arrangement comprises a suction lumen having a second flowcross-section, wherein a cross section ratio between said first flowcross-section and said second flow cross-section is not less than about1.10. For example, said cross section ratio is between about 1.10 andabout 1.5.

In at least a second form of carrying out the method, said arterial flowexchange system comprises a first arterial device and a second arterialdevice separate from said first arterial device, and said distal portionarrangement comprises a distal portion of said first arterial device anda distal portion of said second device, wherein said first arterialdevice and said second arterial device are independently accommodatedinto the aorta, wherein said perfusion lumen arrangement comprises atleast a first perfusion lumen comprised in said first arterial device,and at least one second perfusion lumen comprised in said secondarterial device, and wherein said suction lumen arrangement comprises atleast one suction lumen comprised in said second arterial device. Forexample, said first arterial device is operated to provide said nominalperfusion flow rate via said at least one first perfusion lumen and atleast one respective said perfusion outlet comprised in said firstarterial device, wherein said second arterial device is operated toprovide said excess perfusion flow rate via said at least one secondperfusion lumen and at least one respective said perfusion outletcomprised in said second arterial device, and wherein said secondarterial device is further operated to provide said suction flow ratevia said suction lumen and at least one said suction inlet comprised insaid second arterial device.

According to the first aspect of the invention, the method for removingembolic debris from an aorta of a patient having a body bloodcirculation system, may further comprise one or more of the followingfeatures in any combination or permutation:

-   -   wherein said nominal perfusion flow rate is provided in the        range between about 3 liters per minute to about 5 liters per        minute;    -   wherein said target flow rate is provided in the range between        about 3.3 liters per minute to about 7.5 liters per minute;    -   wherein said excess perfusion flow rate is provided in the range        between about 0.3 liters per minute to about 2.5 liters per        minute;    -   wherein said suction flow rate is greater than 0.5 liters per        minute; r    -   wherein said suction flow rate is greater than 0.75 liters per        minute; wherein said suction flow rate is greater than 1 liter        per minute;    -   wherein said suction flow rate is greater than 1.25 liters per        minute;    -   wherein said suction flow rate is in the range between about 0.5        liters per minute to about 2.0 liters per minute;    -   wherein said suction flow rate is in the range between about 0.5        liters per minute to about 2.5 liters per minute;    -   wherein said suction flow rate is in the range between about        0.75 liters per minute to about 2.5 liters per minute.

According to a second aspect of the invention there is provided anarterial device, for use with a patient having an aorta and a body bloodcirculation system, the arterial device comprising a distal portionarrangement configured for being accommodated in the aorta of thepatient in use of the system, said distal portion arrangementcomprising:

-   -   a perfusion lumen arrangement having at least one perfusion        outlet and connectable to at least one perfusion source, wherein        said perfusion lumen arrangement is configured for providing        therethrough a perfusion flow into the aorta (via said at least        one perfusion outlet), said perfusion flow having a perfusion        flow rate;    -   and    -   a suction lumen arrangement having at least one suction inlet        and connectable to a suction source, said suction lumen        arrangement being configured for providing a suction flow out of        the aorta (via said at least one suction inlet), said suction        flow having a suction flow rate;    -   wherein said suction flow rate is greater than 0.5 liters per        minute.

The arterial device according to the second aspect of the invention maycomprise any one of the following features (a2) to (d2), or more thanone of the following features (a2) to (d2), in any combination orpermutation:

-   -   (a2) wherein said suction lumen arrangement is configured for        providing said suction flow rate at a corresponding suction flow        velocity that is below a threshold value for avoiding or        minimizing damage to blood cells.    -   (b2) wherein said perfusion flow rate comprises a target        perfusion flow rate that is greater than a nominal perfusion        flow rate by an excess perfusion flow rate, wherein said nominal        perfusion flow is sufficient for providing adequate fluid flow        to the body blood circulation system of the patient.    -   (c2) wherein said distal portion is configured for providing        fluid communication between at least one said perfusion outlet        and at least one said suction inlet within the aorta via an        outside of said distal portion, in use of the arterial device.    -   (d2) wherein said distal portion is configured for providing        fluid communication between at least one said perfusion outlet        and at least one said suction inlet within the aorta via an        outside of said distal portion, in use of the arterial device.

Furthermore, the arterial device according to the second aspect of theinvention may comprise any one of the following features (A2) to (I2),or more than one of the following features (A2) to (I2), in anycombination or permutation:

-   -   (A2) wherein said arterial device is configured for enabling        selectively matching said suction flow rate with said excess        perfusion flow rate according to a desired matching level,        defined as a percentage of said suction flow rate with respect        to said excess perfusion flow rate. For example, said matching        level may be about 100%, or may be greater than 100%. For        example, said matching level may be in a range between about 50%        and about 100%.    -   (B2) wherein said target perfusion flow rate is a first        proportion of said nominal perfusion flow rate, wherein said        first proportion is not less than about 110% of said nominal        perfusion flow rate. For example, said first proportion may be        between about 110% and about 150% of said nominal perfusion flow        rate, or, for example, said first proportion may be between        about 115% and about 160% of said nominal perfusion flow rate,        or, for example, said first proportion may be between about 120%        and about 150% of said nominal perfusion flow rate, or, for        example, said first proportion may be between about 120% and        about 170% of said nominal perfusion flow rate.    -   (C2) wherein said suction flow rate is a second proportion of a        said nominal perfusion flow rate, wherein said second proportion        is not less than about 10% of said nominal perfusion flow rate.        For example, said second proportion may be between about 10% and        about 50% of said nominal perfusion flow rate, or, for example,        said second proportion may be between about 15% and about 60% of        said nominal perfusion flow rate, or, for example, said second        proportion may be between about 20% and about 50% of said        nominal perfusion flow rate, or, for example, said second        proportion may be between about 20% and about 70% of said        nominal perfusion flow rate.    -   (D2) wherein said arterial device is configured for operating in        the aorta to provide said excess perfusion flow rate and to        provide said suction flow rate in the absence of establishing        occlusion of the aorta at least in a region of the aorta        corresponding to a part of the arterial device extending between        said at least one suction inlet and said at least one perfusion        outlet.    -   (E2) wherein said device having an absence of an occlusion        arrangement that is otherwise configured for providing occlusion        of the aorta in operation of said arterial device, at least        between said at least one suction inlet and said at least one        perfusion outlet.    -   (F2) wherein said arterial device is configured for providing at        least one said suction inlet within the ascending aorta of the        patient in operation of the arterial device.    -   (G2) wherein said flow exchange arterial device is configured in        operation of the arterial device for causing at least a majority        of embolic debris that may be present in the aorta to be        diverted to said at least one suction inlet at least from        upstream of said at least one suction inlet.    -   (H2) wherein said arterial device is configured for providing        said target perfusion flow rate wherein a corresponding target        perfusion flow velocity is below a threshold value for avoiding        or minimizing damage to blood cells.    -   (I2) wherein said distal portion arrangement comprises at least        one additional suction outlet port configured for de-airing the        aorta by facilitating removing of said embolic debris in the        form of air bubbles.

In at least a first group of embodiments according to the second aspectof the invention, said arterial device, optionally comprising any one offeatures (a2) to (d2) or (A2) to (I2), or more than one of features (a2)to (d2) and/or (A2) to (I2) in any combination or permutation, is in theform of an aortic cannula, wherein said distal portion is configured forbeing introduced into the aorta via a wall of the ascending aorta. In atleast one such embodiment of said first group, said distal portioncomprises a curved portion and a distal end, wherein said distal endcomprises said at least one perfusion outlet, and wherein said curvedportion comprises said at least one suction inlet. In operation said atleast one perfusion outlet is facing in a generally downstream directionalong the aorta and said at least one suction inlet is facing in agenerally upstream direction along the aorta. Additionally oralternatively, said perfusion lumen arrangement comprises a first lumen,wherein said suction lumen arrangement comprises a second lumen, andwherein said first lumen and said second lumen are integrally formed insaid distal portion. The first lumen may have a first flow cross-sectionand said second lumen may have a second flow cross-section, wherein across section ratio between said first flow cross-section and saidsecond flow cross-section is not less than about 1.10. For example, saidcross section ratio is between about 1.10 and about 10.0. In at leastsome such embodiments of said first group, said distal portion comprisesone said perfusion outlet and one said suction inlet.

In at least a second group of embodiments according to the second aspectof the invention, said arterial device, optionally comprising any one offeatures (a2) to (d2) or (A2) to (I2), or more than one of features (a2)to (d2) and/or (A2) to (I2) in any combination or permutation, is in theform of an aortic catheter, wherein said distal portion is configuredfor being introduced into the aorta via an entry point at a locationdownstream of the descending aorta, the distal portion being furtherconfigured for being navigated upstream to the ascending aorta. In atleast some such embodiments of said second group, said distal portioncomprises a distal end and an elongate portion extending proximally fromsaid distal end, wherein said distal end comprises said at least oneperfusion outlet, and wherein said elongate portion comprises said atleast one suction inlet. In operation said at least one perfusion outletis downstream of said at least one suction inlet with respect toantegrade flow in the aorta. In at least some such embodiments of saidsecond group of embodiments, said at least one suction inlet is facingin a generally upstream direction along the aorta in operation of thearterial device. Optionally, said perfusion lumen arrangement comprisesa first lumen and said suction lumen arrangement comprises a secondlumen, and wherein said first lumen and said second lumen are integrallyformed coaxially in said distal portion. Said first lumen may have afirst flow cross-section and said second lumen may have a second flowcross-section, wherein a cross section ratio between said first flowcross-section and said second flow cross-section is not less than about1.10. For example, said cross section ratio is between about 1.10 andabout 10. In some such embodiments, said distal portion comprises aplurality of said perfusion outlets and one said suction inlet; in othersuch embodiments, said distal portion comprises a plurality of saidperfusion outlets and a plurality of said suction inlets; optionally ineither case, said plurality of perfusion outlet ports comprises at leasta first group of said perfusion outlet ports and a second group of saidperfusion outlet ports, wherein said second group of said perfusionoutlet ports is located proximally of said first group of said perfusionoutlet ports, and wherein said first group of said perfusion outletports is located within the ascending aorta or aortic arch in operationof the arterial device.

According to the second aspect of the invention, the arterial device, asdefined above, optionally comprising any one of features (a2) to (d2)and/or (A2) to (I2), or more than one of features (a2) to (d2) and/or(A2) to (I2) in any combination or permutation, and/or according to theaforementioned first group of embodiments or according to theaforementioned second group of embodiments of the arterial device, maybe further configured according to any one of the following features, oraccording to more than one of the following features in any combinationor permutation:

-   -   (J2) wherein said nominal perfusion flow rate is in the range        between about 3 liters per minute to about 5 liters per minute;    -   (K2) wherein said target flow rate is in the range between about        3.3 liters per minute to about 7.5 liters per minute;    -   (L2) wherein said excess perfusion flow rate is in the range        between about 0.3 liters per minute to about 2.5 liters per        minute;    -   (M2) wherein said suction flow rate is greater than 0.75 liters        per minute; wherein said suction flow rate is greater than 1        liter per minute;    -   (N2) wherein said suction flow rate is greater than 1.25 liters        per minute;    -   (O2) wherein said suction flow rate is in the range between        about 0.5 liters per minute to about 2.0 liters per minute;    -   (P2) wherein said suction flow rate is in the range between        about 0.5 liters per minute to about 2.5 liters per minute;    -   (Q2) wherein said suction flow rate is in the range between        about 0.75 liters per minute to about 2.5 liters per minute.

According to the second aspect of the invention, there is also providedan arterial system for use with a patient having an aorta and a bodyblood circulation system, comprising:

-   -   an arterial device as defined herein according to the second        aspect of the invention;    -   a controller, configured, in use of the arterial system, for:        -   selectively controllably providing a target perfusion flow            into the aorta at said target perfusion flow rate;        -   selectively controllably providing a suction flow out of the            aorta at said suction flow rate; and        -   selectively controlling said target perfusion flow rate and            said suction flow rate concurrently to cause embolic debris            that may be present in the aorta to be diverted to said at            least one suction inlet.

In operation of the arterial system according to the second aspect ofthe invention, said perfusion lumen arrangement is connected to said atleast one perfusion source, and said suction lumen arrangement isconnected to said suction source.

According to the second aspect of the invention there is also provided amethod for removing embolic debris from an aorta of a patient having abody blood circulation system, comprising:

-   -   providing an arterial device according to the second aspect of        the invention;    -   accommodating a distal portion arrangement of the device in the        aorta of the patient so that at least at least one said suction        inlet port is accommodated in the ascending aorta of the        patient;    -   controllably providing a suction flow out of the aorta at said        suction flow rate, wherein said suction flow rate is greater        than 0.5 liters per minute.

Additionally, the method may also comprise the following steps:

-   -   controllably providing a target perfusion flow into the aorta at        said target perfusion flow rate; and    -   selectively controlling said target perfusion flow rate and said        suction flow rate to cause embolic debris that may be present in        the aorta to be diverted to said at least one suction inlet.

According to at least some aspects of the invention, there is providedan arterial device, system and method are provided for use with apatient undergoing a cardiac procedure. The system is configured forenabling one or more arterial devices to be accommodated in the aorta ofthe patient in use of the system, and a perfusion lumen arrangementprovides therethrough a target perfusion flow into the aorta having atarget perfusion flow rate that is significantly greater than a nominalperfusion flow rate, by an excess perfusion flow rate. A suction lumenarrangement provides therethrough a suction flow out of the aorta at asuction flow rate. The target perfusion flow rate and the suction flowrate may be concurrently and selectively controlled to cause embolicdebris that may be present in the aorta to be diverted to the suctioninlet, while providing the nominal flow rate to the body circulation ofthe patient.

Herein, the term “distal” refers to a direction generally towards theinside of the body from an outside thereof, while the term “proximal”refers to a direction generally towards the outside of the body from aninside thereof.

Herein, “nominal perfusion flow” refers to a perfusion flow that is theminimum sufficient for providing adequate fluid flow to the body bloodcirculation system of the patient, i.e., a minimum perfusion flow havinga corresponding nominal perfusion flow rate that is sufficient tosustain the full metabolic demands of the patient. In practice, apatient may have an actual perfusion flow rate, normally provided by theheart, that can vary within a range, and this range may change accordingto the respective condition of the patient, and depend on variousfactors that define this condition, for example including one or more ofstate of health, body temperature, body activity and so on. Thus, thenominal perfusion flow rate herein refers to the minimum perfusion flowrate of the range of perfusion flow rates for the respective conditionof the patient. The nominal perfusion flow rate is in practiceconventionally determined by the medical staff carrying out therespective cardiac procedure, and there are a number of standardconventional methods commonly used for determining the nominal perfusionflow rate for a particular patient. For example, one such method isbased on body surface area (BSA), and a fixed perfusion flow rate persquare meter of body surface of the patient is provided. This fixedperfusion flow rate per square meter of body surface of the patient maybe, for example, about 2.4 liters per minute per square meter, and thus,for example, a patient having a BSA of 1.8 m² would have a nominalperfusion flow rate of about 4.3 liters/min (=2.4*1.8). In some cases,the fixed perfusion flow rate per square meter of body surface of thepatient may be different from 2.4 liters per minute per square meter—forexample 2.3 liters per minute per square meter, or 2.5 liters per minuteper square meter. Other methods may be used for determining the nominalperfusion flow rate for the patient, for example employing known dynamiccalculation that may change the nominal perfusion flow rate during thecardiac procedure.

The “body blood circulation system” of the patient herein includes thecorporeal body circulation system and the cerebral circulation systemwhich are normally supplied by the aorta.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carriedout in practice, embodiments will now be described, by way ofnon-limiting example only, with reference to the accompanying drawings,in which:

FIG. 1 is a simplified schematic illustration of the general anatomy ofthe aorta.

FIG. 2 is a schematic illustration of an aortic system according to afirst embodiment of the invention, wherein the respective aortic deviceis installed in the aorta.

FIG. 3 is a cross-sectional side view of the aortic device of theembodiment of FIG. 2; FIG. 3 a is a cross-sectional side view of analternative variation of the embodiment of FIG. 3.

FIG. 4 is a side view of the aortic device of the embodiment of FIG. 3;FIG. 4 a to FIG. 4 o are a series of cross-sectional views of thearterial device of the embodiment of FIG. 2, taken along sections 0 to28, respectively, of FIG. 4; FIG. 4 p is a top view of the embodiment ofFIG. 4; FIG. 4 q is a transverse cross-section of the embodiment of FIG.4 p taken along A-A.

FIG. 5 illustrates schematically perfusion and suction flows within theaorta using the embodiment of FIG. 1.

FIG. 6 illustrates schematically perfusion and suction flows within theaorta using the embodiment of FIG. 1, where the suction flow rate isbelow a threshold value.

FIG. 7 illustrates schematically perfusion and suction flows within theaorta using the embodiment of FIG. 1, where the suction flow rate is ator above a threshold value.

FIG. 8 is a cross-sectional side view of an alternative variation of thearterial device of the embodiment of FIG. 2, and schematicallyillustrates perfusion and suction flows within the aorta using the same.

FIG. 9 is a cross-sectional side view of another alternative variationof the arterial device of the embodiment of FIG. 2, and schematicallyillustrates perfusion and suction flows within the aorta using the same.

FIG. 10 is a schematic illustration of an aortic system according to asecond embodiment of the invention, wherein the respective arterialdevice is installed in the aorta.

FIG. 11 is a cross-sectional side view of the arterial device of theembodiment of FIG. 10.

FIG. 12 is a cross-sectional side view of an alternative variation ofthe arterial device of the embodiment of FIGS. 10 and 11.

FIG. 13 is a schematic illustration of an aortic system according to athird embodiment of the invention, wherein the respective arterialdevices are installed in the aorta.

FIG. 14 is a schematic illustration of an aortic system according to afourth embodiment of the invention, wherein the respective arterialdevices are installed in the aorta.

DETAILED DESCRIPTION OF EMBODIMENTS

By way of general background, FIG. 1 illustrates schematically theanatomy of the aorta 1, which is the main blood conduit of a series ofblood vessels which transport oxygenated blood from the heart to thebody tissues of a patient. The aorta is, for ease of reference, dividedinto the following portions: the ascending aorta 2, the aortic arch 3,and the descending aorta 4. The ascending aorta 2 extends from the upperpart of the left ventricle of the heart 9 to the upstream end 3U of theaortic arch 3. The aortic arch 3 has three branches—the innominateartery 5 (also referred to as the brachiocephalic artery), the leftcommon carotid artery 6 and the left subclavian artery 7—which supplyoxygenated blood to the cerebral circulation system. The descendingaorta 4 starts at the downstream end 3D of the aortic arch 3 andsupplies oxygenated blood to the corporeal body circulation system. Thedescending aorta 4 continues through the abdomen and splits into the twocommon iliac arteries 8 that supply oxygenated blood to the lowerextremities of the body.

Referring to FIGS. 2 and 3 an arterial system according to a firstembodiment of the invention, generally designated with reference numeral100, comprises an arterial flow exchange system in the form of arterialdevice 200 (also referred to interchangeably herein as an aortic device)and a controller 300.

Arterial device 200 is in the form of an aortic cannula, in particularan aortic double-lumen cannula, comprising a distal portion 201 that isconfigured for being inserted into and accommodated within the aorta 1,in particular the ascending aorta 2, during operation of the system 100,and a proximal portion 202 that is configured for concurrently remainingoutside of the aorta 1.

Device 200 comprises two internal lumens—a perfusion lumen 210 and anaspiration or suction lumen 220.

Distal portion 201 is in the form of a generally tubular elongate member230, comprising a double lumen interior defining a respective distalperfusion lumen portion 210 a of perfusion lumen 210, and a respectivedistal suction lumen portion 220 a of suction lumen 220. Distal portion201 further comprises a perfusion outlet port 240 and a suction inletport 250.

Proximal portion 202 projects proximally from distal portion 201 andbranches off from a generally tubular base member 232 having a doublelumen interior contiguous with the double lumen interior of the distalportion 201, to two separate tubular members 234, 236 each continuingone or another of the lumens, thereby defining a respective proximalperfusion lumen portion 210 b of perfusion lumen 210 and a respectiveproximal suction lumen portion 220 b of suction lumen 220. The proximalportion 202 further comprises a perfusion inlet port 245 and a suctionoutlet port 255 at the proximal end 203 of the proximal portion 202, onthe tubular members 234, 236 respectively.

The perfusion lumen 210 thus extends contiguously between the perfusioninlet port 245 and the perfusion outlet port 240, and provides fluidcommunication therebetween, via the proximal perfusion lumen portion 210b and the distal perfusion lumen portion 210 a. Similarly, the suctionlumen 220 thus extends contiguously from the suction outlet port 255 tothe suction inlet port 250, and provides fluid communicationtherebetween, via the proximal suction lumen portion 220 b and thedistal suction lumen portion 220 a.

The device 200 comprises an outer casing 237 and an internal partitionwall 235 that separates the perfusion lumen 210 from the suction lumen220 in the distal portion 201 and the base member 232.

Referring also to FIGS. 4 to 4 q, the perfusion lumen 210 is gentlycurved between the perfusion inlet port 245 and the perfusion outletport 240, and has a transverse cross-section that smoothly changesbetween a generally circular form both at the perfusion inlet port 245and at the perfusion outlet port 240, to a generally oblate form at anintermediate portion of the perfusion lumen 210 corresponding to thelocation of the partition wall 235. The curved path of the perfusionlumen 210 provides a net change in the direction of perfusion flowbetween the perfusion inlet port 245 and the perfusion outlet port 240corresponding to angle α between the longitudinal axis A of theperfusion lumen 210 at the perfusion inlet port 245 and the longitudinalaxis B of the perfusion lumen 210 at the perfusion outlet port 240. Thegradual change in the flow direction of the perfusion flow in theperfusion lumen minimizes risk of haemolysis, for example, and enablesrelatively large perfusion flow rates to be provided to the aorta viathe perfusion lumen 210.

In this embodiment, angle α is about 110 degrees, though in alternativevariations of this embodiment angle α may be between about 90 degreesand about 180 degrees, for example.

Similarly, the suction lumen 220 is also gently curved between thesuction outlet port 255 and the suction inlet port 250, and has atransverse cross-section than smoothly changes between a generallycircular form at the suction outlet port 255 and a generally oblate format the suction inlet port 240 and extending proximally along a portionof the suction lumen 220 corresponding to the location of the partitionwall 235.

Thus, elongate member 230 is also mildly curved, and perfusion outletport 240 is provided at the distal end 204 of the device 200, so that inuse, the perfusion outlet port 240 faces the general downstream(antegrade) flow direction Q of the aorta. Distal edge 241 of theperfusion outlet port 240 is rounded (although in alternative variationsof this embodiment this distal edge may be tapered or otherwise curved)to facilitate entry into the aorta 1. The perfusion outlet port 240 isalso scarfed with respect to the perfusion lumen 210, and thus the planeof edge 241 is at an acute angle θ to a reference plane RP that isnormal to the axis B. In this embodiment, angle θ is about 30 degrees,though in alternative variations of this embodiment angle θ may bebetween about 0 degrees and about 60 degrees, for example. The scarfingof perfusion outlet port 240 also facilitates entry of the distalportion 201 into the aorta 1.

The suction inlet port 250 is provided at the outer bend of the curvedelongate member 230, generally opposed to the position of the perfusionoutlet port 240 along axis B, so that in use of the device 200 thesuction inlet port 250 faces the general upstream (retrograde) flowdirection S of the aorta. The outer edge 251 of suction inlet port 250is also scarfed in this embodiment and blends with the outer curvedprofile of the outside 338 of the distal portion 201, providing arelatively large inlet area as compared with the transversecross-section of the suction lumen 220 in proximity to suction inletport 250.

In operation of the device 200 and system 100, the suction inlet port250 is upstream of the perfusion outlet port 240.

Device 200 is configured for operating within an artery, in particularthe aorta 1, more in particular the ascending aorta 2, in a manner toprovide fluid communication between the perfusion outlet port 240 andthe suction inlet port 250 within the artery, aorta or ascending aorta,respectively, via the outside 338 of the distal portion 201 of thedevice 200.

Thus, distal portion 201 has an outside 338 (also referred tointerchangeably herein as an outer surface of the distal portion 201)that in use of the device 200 does not occlude or otherwise obstruct theartery, aorta or ascending aorta in which the distal portion 201 isinserted, in particular within a region of the corresponding bloodvessel between the location of the suction inlet port 250 and thelocation of the perfusion outlet port 240. Furthermore, the device 200,and in particular the distal portion 201, has an absence of anyocclusion arrangement that is otherwise configured for occluding ofobstructing the artery, in particular the aorta, more particularly theascending aorta during use of the device such as to prevent such fluidcommunication between the perfusion outlet port 240 and the suctioninlet port 250 via the outside 338.

In alternative variations of this embodiment in which the distal portionmay be configured with one or more occlusion devices (for exampleinflatable balloons) positioned at a location inbetween the location ofthe suction inlet port and the location of the perfusion outlet port,and having an inoperative state in which the occlusion device does notocclude the blood vessel in which the device is installed, and anoperative state in which the occlusion device occludes or blocks theblood vessel, such a device is operated with the occlusion device in theaforementioned inoperative state, or at least not in the aforementionedoperative state—see for example the embodiment illustrated in FIG. 8.

In operation of the device 200 the suction inlet port 250 is in aposition upstream of the perfusion outlet port 240, with respect to theantegrade flow direction Q.

At the distal end of the proximal portion 202 there is provided a collar239. In use of the device 200, collar 239 abuts against an outer surfaceof the blood vessel in which the device is inserted, typically the aorta1 and particularly the ascending aorta 2, and acts as a stop, preventingthe device 200 from being inserted further. The location of the collar239 with respect to the device 200 is also such as to ensure that whenthe device 200 is installed in the respective blood vessel, the outside238 is suitably spaced from the internal walls of the blood vessel. Inthis embodiment the location of the collar 239 with respect to thedevice 200 is also such as to ensure that when the device 200 isinstalled in the respective blood vessel the perfusion outlet port 240and/or the suction inlet port 250 is also centrally located within theblood vessel, i.e. centrally located with respect to the aortic lumen,so that the perfusion outlet port 240 and/or the suction inlet port 250,respectively, is generally uniformly spaced with respect to the internalwalls of the blood vessel. In alternative variations of this embodiment,the collar 239 may be located with respect to the device 200 such as toensure that when the device 200 is installed in the respective bloodvessel the perfusion outlet port 240 is closer spaced with respect toone part than with respect to another part of the internal walls of theblood vessel.

The device 200 may be formed from substantially rigid and/or semi-rigidand medically compatible materials, including, for example medicallysuitable plastics, silicon, rubber or composite materials that are knownin the art for use in aortic cannulation devices. The device 200 maythus be configured as disposable device, being made from disposablematerials and disposed of after use with a patient. Alternatively, thedevice may be configured as an autoclavable or otherwise sterilizableand non-disposable device, and formed from stainless steel, titanium orother suitable metals or alloys or any other suitable materials.

Perfusion lumen 210 is configured for providing at least a nominalperfusion flow, i.e., having a nominal perfusion blood flow rate NFR,that is the minimum sufficient for providing adequate fluid flow to thebody blood circulation system of the patient, i.e., a perfusion flowrate that is sufficient to sustain the minimum metabolic demands of thepatient. In other words, the nominal perfusion flow comprises a fluidincluding oxygenated blood provided by the extra-corporeal bloodoxygenation system (but may also comprise other fluids, for examplesaline solution), and corresponds to the blood flow that is the minimumnormally provided to the aortic arch and the descending aorta of thepatient by the heart of the patient at similar conditions. In practice,the nominal perfusion flow rate NFR is determined by the medical staffaccording to conventional practice, as discussed above in the “SUMMARYOF INVENTION” section above. Such nominal perfusion flow rate NFR isprovided at a nominal flow velocity NFV that is below a threshold valueV. The threshold value V is a flow velocity that above which isconsidered may cause haemolysis or other damage to the blood, forexample due to the corresponding shear stresses induced in the blood.

In particular, the perfusion lumen 210 is configured for providing atarget perfusion flow having a target perfusion flow rate TFR that issignificantly greater than the aforesaid nominal perfusion flow rate NFRby a factor ΔFR, referred to herein the excess perfusion flow rate (andalso referred to herein interchangeably as the “excess flow rate”). Inother words:TFR=NFR+ΔFR

The perfusion lumen 210 is configured for providing a maximum targetperfusion flow having a corresponding maximum target perfusion flow rateTFR_(max) that is greater than the aforesaid nominal perfusion flow rateNFR by a corresponding maximum excess perfusion flow rate ΔFR_(max),i.e.,TFR_(max)=NFR+ΔFR_(max)

Thus, in this embodiment, the perfusion lumen 210 comprises a minimumcross-sectional flow area that is correspondingly larger than would beotherwise be required for providing only the nominal perfusion flow rateNFR, in order to enable flow rates of up to the aforesaid maximum targetperfusion flow rate TFR_(max), but still at the flow velocities whichare still below the aforesaid threshold value V.

In this embodiment, and by way of example, the perfusion lumen isconfigured for providing maximum target perfusion flow rate TFR_(max)that is about 150% of the nominal perfusion flow rate NFR, and thus thecorresponding maximum excess perfusion flow rate ΔFR_(max), iscorrespondingly about 50% of the nominal perfusion flow rate NFR.

In this embodiment, the perfusion lumen is configured for providingmaximum target perfusion flow rate TFR_(max) of greater than about 5.5or 6 or 6.5 or 7 or 7.5 liters/minute, and a nominal perfusion flow rateNFR of about 4 to 5 liters/minute, depending on the particulars of thepatient, for example, while the target perfusion flow rate TFR may varyin a range between about 3.3 l/min to about 4.5 l/min at nominalperfusion flow rate NFR of about 3 l/min, or wherein the targetperfusion flow rate TFR may vary in a range between about 4.4 l/min toabout 6 l/min at nominal perfusion flow rate NFR of about 4 l/min,increasing to a range between about 5.5 l/min to about 7.5 l/min atnominal perfusion flow rate NFR of about 5 l/min.

Thus, in this embodiment and at least some alternative variations ofthis embodiment of the invention, the target perfusion rate may thusvary between a minimum of about 110% of the nominal flow rate NFR, to amaximum of about 150%. In at least some other alternative variations ofthis embodiment or in other embodiments of the invention, the targetperfusion rate may vary between a minimum of about 115% of the nominalflow rate NFR, to a maximum of about 150%. In at least some otheralternative variations of this embodiment or in other embodiments of theinvention, the target perfusion rate may vary between a minimum of about115% of the nominal flow rate NFR, to a maximum of about 160%. In atleast some other alternative variations of this embodiment or in otherembodiments of the invention, the target perfusion rate may vary betweena minimum of about 120% of the nominal flow rate NFR, to a maximum ofabout 150%. In at least some other alternative variations of thisembodiment or in other embodiments of the invention, the targetperfusion rate may vary between a minimum of about 125% of the nominalflow rate NFR, to a maximum of about 150%. In at least some otheralternative variations of this embodiment or in other embodiments of theinvention, the target perfusion rate may vary between a minimum of about110% of the nominal flow rate NFR, to a maximum of about 175%. In atleast some other alternative variations of this embodiment or in otherembodiments of the invention, the target perfusion rate may vary betweena minimum of about 115% of the nominal flow rate NFR, to a maximum ofabout 175%. In at least some other alternative variations of thisembodiment or in other embodiments of the invention, the targetperfusion rate may vary between a minimum of about 120% of the nominalflow rate NFR, to a maximum of about 175%. In at least some otheralternative variations of this embodiment or in other embodiments of theinvention, the target perfusion rate may vary between a minimum of about125% of the nominal flow rate NFR, to a maximum of about 175%. In atleast some other alternative variations of this embodiment or in otherembodiments of the invention, the target perfusion rate may vary betweena minimum of about 120% of the nominal flow rate NFR, to a maximum ofabout 170%.

In this embodiment, and by way of example, the perfusion lumen 210 hasan internal diameter of about 7.7 cm at the perfusion inlet port 245 andan internal diameter of about 7.6 cm at the perfusion outlet port 240.The suction lumen 220 has an internal diameter of about 4.4 cm at thesuction outlet port 255, and the suction inlet port 250 has a maximumwidth of about 8.8 cm due to the scarfing thereof. Furthermore, by wayof further example, FIG. 4 a to FIG. 4 o show geometrically consistentand accurate cross-sections of the embodiment of FIG. 4, taken alongnumerically labeled sections “0” to “28”, respectively, of FIG. 4. It isto be further noted that the numerical label for each of these sectionsrefers to a spacing in mm of the respective section from the firstsection illustrated in FIG. 4 a. Thus, for example, FIG. 4 j refers tothe cross-section at section “18”, which is at 18 mm from the sectiondepicted in FIG. 4 a. As a datum, section 12 illustrated in FIG. 4 g isat the proximal end of the distal portion of the device.

The nominal perfusion blood flow rate NFR may of course vary frompatient to patient, and is generally a function of, inter alia, bodyweight, age, sex and general health of the particular patient, and mayalso vary with time, activity and so on. However, according to at leastthis embodiment of the invention, the target perfusion flow rate TFR andthe maximum target perfusion flow rate TFR_(max) are related to thespecific nominal perfusion blood flow rate NFR that is unique to theparticular patient that is being treated with the system 100 and device200, as determined by the medical staff treating the patient.

The suction lumen 220 has a minimum cross-sectional flow area that issmaller than the minimum cross-sectional flow area of the perfusionlumen 210, and in this embodiment is configured for providing a suctionflow rate SFR that can be varied from zero to a maximum suction flowrate SFR_(max) that is generally similar to the corresponding maximumexcess perfusion flow rate ΔFR_(max).

The perfusion inlet port 245 is configured for being connected to, andthus for receiving oxygenated blood from, a suitable perfusion source320, for example a heart lung machine (also referred to interchangeablyherein as a bypass-oxygenator machine) or any other extra-corporealblood oxygenation system, which are well known in the art, and of whichthere exist many commercially available examples.

A suitable pump 325, for example a peristaltic pump, pumps oxygenatedblood from the perfusion source 320 to the device 200. Pump 325 isconfigured for providing a controllable perfusion flow rate at least upto the maximum target perfusion flow rate TFR_(max) for the particularpatient being treated by system 100, and is variably controllable (bycontroller 300) to provide perfusion flow rates from nominally zero toat least up to the maximum target perfusion flow rate TFR_(max).

The pump 325 is operatively connected to, and is controlled by,controller 300. Thus, controller 300 is configured for controlling thepump 325 to provide any desired perfusion flow rate in the range betweenzero and at least the maximum target perfusion flow rate TFR_(max).

The suction outlet port 255 is configured for being connected to, andthus for returning blood to, a suitable suction source 345, for examplein the form of a medical suction pump, for example a peristaltic pump.Suitable medical suction pumps capable of aspirating or sucking bloodare well known in the art, and of which there exists many commerciallyavailable examples. In alternative variations of this embodiment, thesuction source 345 may comprise a fluid suction line, suitable forsuctioning blood or other liquids. In any case, the suction source 345is selectively controllable, and is operatively connected to, and iscontrolled by, controller 300.

The suction source 345 is configured for providing a variablycontrollable suction flow rate from nominally zero to at least themaximum suction flow rate SFR_(max). The controller 300 is configuredfor selectively controlling the suction source 345 to provide anydesired suction flow rate in the range between zero and at least themaximum suction flow rate SFR_(max).

In at least some operational modes of the system 100, the suction source345 sucks or aspirates blood via the device 200 and into a suitablereceiving volume 340. In some alternative variations of this embodiment,the blood collected at receiving volume 340 may be subsequently suitablyprocessed to remove embolic debris and may be then supplied to theperfusion source 320 to provide a closed system.

Thus, in this embodiment and at least some alternative variations ofthis embodiment of the invention, the suction flow rate may thus varybetween a minimum of about 10% of the nominal flow rate NFR, to amaximum of about 50%. In at least some other alternative variations ofthis embodiment or in other embodiments of the invention, the suctionflow rate may vary between a minimum of about 15% of the nominal flowrate NFR, to a maximum of about 50%. In at least some other alternativevariations of this embodiment or in other embodiments of the invention,the suction flow rate may vary between a minimum of about 15% of thenominal flow rate NFR, to a maximum of about 60%. In at least some otheralternative variations of this embodiment or in other embodiments of theinvention, the suction flow rate may vary between a minimum of about 20%of the nominal flow rate NFR, to a maximum of about 50%. In at leastsome other alternative variations of this embodiment or in otherembodiments of the invention, the suction flow rate may vary between aminimum of about 25% of the nominal flow rate NFR, to a maximum of about50%. In at least some other alternative variations of this embodiment orin other embodiments of the invention, the suction flow rate may varybetween a minimum of about 10% of the nominal flow rate NFR, to amaximum of about 75%. In at least some other alternative variations ofthis embodiment or in other embodiments of the invention, the suctionflow rate may vary between a minimum of about 15% of the nominal flowrate NFR, to a maximum of about 75%. In at least some other alternativevariations of this embodiment or in other embodiments of the invention,the suction flow rate may vary between a minimum of about 20% of thenominal flow rate NFR, to a maximum of about 75%. In at least some otheralternative variations of this embodiment or in other embodiments of theinvention, the suction flow rate may vary between a minimum of about 25%of the nominal flow rate NFR, to a maximum of about 75%. In at leastsome other alternative variations of this embodiment or in otherembodiments of the invention, the suction flow rate may vary between aminimum of about 20% of the nominal flow rate NFR, to a maximum of about70%.

Thus, in operation the system 100 comprises arterial device 200 andextra-corporeal circulation system 290, which comprises controller 300,pump 325, perfusion source 320 and suction source 345, and optionallyalso receiving volume 340.

In this embodiment, controller 300 comprises a suitable computer systemor the like, which may be preprogrammed to operate the system 100automatically in one or more operating modes, and/or which may beprogrammed for operating in one or more operating modes manually orinteractively, according to operator input. In alternative variations ofthis embodiment, the controller 300 may instead comprise any othersuitable control system, for example an electronic control system, amechanical control system, or a hydraulic control system, eachrespectively configured to selectively provide one or more desiredoperating modes for the system 100.

The system 100 is particularly configured for causing embolic debristhat may be present at least in the ascending aorta 2 to be diverted ordirected to the suction inlet port 250 and out of the aorta 1 via thesuction lumen 220, in particular at least a majority, and preferablyall, the embolic debris, and thus prevent or minimize migration ofembolic debris from the ascending aorta 2 to the aortic arch 3. At thesame time, the system 100 is also configured for providing the patientwith the nominal perfusion flow required for the patient when the heartis not functioning, and/or, for providing the patient with asupplemental perfusion flow required for the patient when the heart isbeginning to function again after cardiac surgery and is not yet itselfproviding the patient with the full required nominal perfusion flow.

As will become apparent, operation of the system 100 to remove theaforesaid embolic debris does not of itself cause or potentially causemore embolic debris to be created. Furthermore the system 100 can beoperated to allow such embolic debris removal operation to be carriedout while providing a nominal perfusion flow to the body circulationsystem, and for the embolic debris removal operation to be phased out,while still providing the required nominal perfusion flow to thepatient's body circulation system. Alternatively, the system 100 can beoperated to continue removing embolic debris, while phasing out thenominal perfusion flow function, as the heart begins to take overperfusion of the body from the extracorporeal circulation system.

The system 100 can thus operate in a number of different operating modesand can switch between different operating modes smoothly. Prior tooperating the system 100, the device 200 must be properly positioned inthe aorta, the distal portion 201 having been introduced and installedin the ascending aorta 2 of the patient for antegrade deployment by anysuitable procedure, for example including any suitable procedure forinstalling a conventional aortic cannulation device. Such a proceduremay include, for example, providing a purse string suture in the wall ofthe ascending aorta, and an aortotomy incision is made inside the pursestring. The distal portion 201 is introduced into the aorta via thisincision, and the device 200 secured in place, for example by suturingthe collar 239 to the wall of the aorta.

Thereafter, the heart 9 may be isolated from the aorta for conductingthe required cardiac procedure or surgery, for example CPB, by closingoff the upstream end of the ascending aorta 2, for example using clampson the outside of the ascending aorta 2, or by using an occlusion devicewithin the ascending aorta, upstream of the distal portion 201, and byproviding oxygenated blood to the body circulation system from perfusionsource 320 via the device 200. The heart may be stopped using any one ofa variety of techniques which are well known in the art, as required forthe cardiac surgery.

Nominal Perfusion Operating Mode

In the nominal perfusion operating mode (NPOM), the system 100 operatesto provide oxygenated blood at least at the nominal perfusion flow rateNFR to the body circulation system. In NPOM mode, the controller 300 isconfigured for controlling the pump 325 to deliver oxygenated blood fromperfusion source 320 to the device 200 via the perfusion lumen 210 atthe nominal perfusion flow rate NFR, while the suction source 345 issubstantially inoperational or on standby, and no significant suction isinduced via the suction lumen 220.

In NPOM mode, the perfusion flow rate may be selectively increased ordecreased according to the metabolic needs of the patient, for example,and the device 200 operates in a manner substantially similar toconventional aortic perfusion cannulation devices.

In NPOM mode, the perfusion flow rate may also be incrementally reducedto zero when the heart is again beating and is in fluid communicationwith the aorta, and the heart takes over perfusion of the bodycirculation. However the NPOM mode is in general only used in thismanner when there is no suspicion or risk of embolic debris that may bepresent and potentially harmful to the patient. Where such a suspicionor risk exists, the embolic debris removal operating mode may be used,as described in greater detail below.

Embolic Debris Removal Operating Mode

In the embolic debris removal operating mode (EROM), the system 100operates to provide oxygenated blood at least at the nominal perfusionflow rate NFR to the body circulation system, while concurrentlyremoving embolic debris and preventing the same from flowing to theaortic arch and possibly therefrom to the cerebral circulation system.

In EROM mode, the controller 300 is configured for controlling the pump325 to deliver oxygenated blood from perfusion source 320 to the device200 via the perfusion lumen 210 at a desired target perfusion flow rateTFR, while controlling the suction source 345 to provide a suction flowrate SFR via the suction lumen 220.

In standard EROM mode, the desired target perfusion flow rate TFR andthe suction flow rate SFR are controlled in a manner to match thesuction flow rate SFR to the excess perfusion flow rate ΔFR thatcorresponds to the target perfusion flow rate TFR, this matching beingaccording to a desired matching level. The desired matching level mayrange from a minimum matching level, in which the suction flow rate SFRis a percentage of the excess perfusion flow rate ΔFR that is less than100%, such as about 25%, though preferably not less than about 50%, to amaximum matching level, in which the suction flow rate SFR is fully(100%) matched to and is substantially equal to the excess perfusionflow rate ΔFR. In some circumstances, the matching level may be evenless than 25%, for example when the patient is experiencing bleeding. Inother circumstances, the matching level may be greater than 100%, forexample when there is a large amount of embolic debris, and the nominalflow rate NFR to the patient is temporarily reduced pro-rate, to avoidhaving to increase the target perfusion rate further.

In regular operation of the system 100 in EROM mode, the matching levelis maintained at about 100%, and the matching level is deviated awayfrom this 100% matching level when there is a special need to do so.

Without being bound by theory, and referring to FIG. 5, the inventorssuggest that by providing a target perfusion flow rate TFR that includesthe nominal perfusion flow rate NFR and the corresponding excessperfusion flow rate ΔFR, and by concurrently providing a suitablesuction flow rate SFR, a recirculation flow field is set up in theascending aorta between the perfusion outlet port 240 and the suctioninlet port 250, which are in fluid communication one with the other inuse of the system. In steady state conditions, an amount of the blood inthe aorta is being continually sucked into the suction lumen 220 via thesuction port 250 at the suction flow rate SFR, and concurrently the sameamount of blood is being replaced by the perfusion flow provided by theperfusion outlet port 240 at a flow rate corresponding to the suctionflow rate SFR, for conservation of mass flow. Thus, at steady state, atleast a proportion P of the target perfusion flow rate TFR iseffectively being recirculated into the ascending aorta in retrogradeflow, and eventually sucked into the suction inlet port 250. Accordingto at least this embodiment of the invention, this proportion P is fullyprovided by all the excess perfusion flow rate ΔFR of the targetperfusion flow rate TFR, so that the remainder of the perfusion flow,i.e., the nominal perfusion flow rate NFR, concurrently continues intothe aortic arch 3 to supply the minimum metabolic needs of the body viathe body circulation system. Thus, the matching level between thesuction flow rate SFR, and the excess perfusion flow rate ΔFR is 100%.In alternative variations of this embodiment, this proportion P is fullyprovided by a first part of the excess perfusion flow rate ΔFR of thetarget perfusion flow rate TFR, so that the remainder of the perfusionflow, i.e., the nominal perfusion flow rate NFR, plus the remainder ofthe excess perfusion flow rate ΔFR concurrently continues into theaortic arch 3 to supply more than the minimum metabolic needs of thebody via the body circulation system, and thus the matching levelbetween the suction flow rate SFR, and the excess perfusion flow rateΔFR is substantially less than 100%.

Referring to FIG. 6, and again without being limited to theory, theinventors suggest that at relatively low levels of suction flow rateSFR, designated herein as SFR_(sub), the recirculation flow field,indicated in the figure by broken line 360, is relatively small and maynot extend to the internal walls 10 of the ascending aorta 2, leaving astagnation zone or “dead zone” DZ in the ascending aorta 2 that issubstantially unaffected by this recirculation flow field. Under theseconditions embolic debris that may exists within the dead zone DZ isalso substantially unaffected by the recirculation field and iseffectively free to migrate to the aortic arch 3, with potentiallyserious consequences to the patient. Under these conditions, even if thetarget perfusion flow rate TFR is further increased but whilemaintaining the low suction flow rate SFR_(sub), the dead zone stillremains, and only the perfusion rate into the body circulation system isincreased to above the nominal perfusion flow rate NFR.

Referring to FIG. 7, and again without being limited to theory, theinventors further suggest that as the suction flow rate SFR is increasedfrom the low suction flow rate SFR_(sub) to a threshold value of suctionflow rate SFR, designated herein as SFR_(threshold), (and concurrentlythe target perfusion rate TPR is also increased to a correspondingthreshold target perfusion rate TPR_(threshold) so that at least aminimum perfusion flow is still being provided to the body circulationsystem at the nominal perfusion flow rate NFR), the recirculation flowfield gets larger to a threshold recirculation flow fieldRFF_(threshold). At this threshold suction flow rate SFR_(threshold),the threshold recirculation flow field RFF_(threshold) is such that theretrograde flow originating from the corresponding proportion P of theincreased target perfusion rate TPR and that is being effectively suckedin via the suction inlet port 250 effectively reduces the dead zone DZto zero, so that the threshold recirculation flow field RFF_(threshold)now occupies the upstream portion of the ascending aorta, or at least sothat the threshold recirculation flow field RFF_(threshold) extends tothe walls 10 of the ascending aorta 2 (the downstream limit of thethreshold recirculation flow field RFF_(threshold) being indicated bythe broken line at 362) such as to effectively prevent migration ofembolic debris into the aortic arch 3 from the ascending aorta 2, or toreduce potential migration of embolic debris. Thus, under theseconditions any embolic debris in the ascending aorta 2 is eventuallydiverted to the suction inlet port 220 and removed via the suctioncannula 220.

Referring still to FIG. 7, and again without being limited to theory,the inventors further suggest that as the suction flow rate SFR isincreased further above the threshold value of suction flow rateSFR_(threshold), (and concurrently the target perfusion rate TPR is alsoincreased from the corresponding threshold target perfusion rateTPR_(threshold) so that at least a minimum perfusion flow is still beingprovided to the body circulation system at the nominal perfusion flowrate NFR), the recirculation flow field RFF gets larger and/or stronger,and is referred to herein as the corresponding closed recirculation flowfield CRFF. Under such conditions, there is even less risk of migrationof embolic debris into the aortic arch 3 than at the aforesaid thresholdsuction flow rate SFR_(threshold), the downstream limit 364 ofcorresponding closed recirculation flow field CRFF moves furtherupstream within the ascending aorta 2.

Thus, the threshold suction flow rate SFR_(threshold) may be defined asthe minimum suction flow rate in which there is significant reduction inmigration of embolic debris into the aortic arch 3 from the ascendingaorta 2, and preferably that such migration of embolic debris iseffectively prevented. While the precise value of the threshold suctionflow rate SFR_(threshold) may vary according to the particularcircumstances of the patient, inventors consider that the thresholdsuction flow rate SFR_(threshold) may vary between about 10% and about25% of the nominal perfusion flow rate NFR for a particular patient.Thus, example of values for the threshold suction flow rateSFR_(threshold) may be 10% or 15% or 20% or 25% of the nominal perfusionflow rate NFR for a particular patient.

Thus, in such conditions, in which the suction flow rate SFR is at orabove the threshold value of suction flow rate SFR_(threshold), (andconcurrently the target perfusion rate TPR is also at or above thecorresponding threshold target perfusion rate TPR_(threshold) so thatperfusion flow is still being provided to the body circulation system atleast at the nominal perfusion flow rate NFR), there is a qualitative aswell as a quantitative change in the characteristics and/or effect ofthe flows provided within the aorta, in particular the ascending aorta,leading to substantial reduction or elimination of migration of embolicdebris into the aortic arch 3, as compared with the flow provided withinthe aorta at much lower flow rates.

In any case, a working value for the threshold suction flow rateSFR_(threshold) may be ascertained or estimated in a number of ways,which may be patient-unique or general. For example, the anatomy andflow parameters of the aorta of the particular patient or of a standardadult aorta (defined in a suitable manner, for example having an anatomythat is averaged across the population or a statistically significantsample thereof) may be physically modeled, so that a physical model ofthe aorta is constructed and tested with suitable particles that modelthe embolic debris. Fluid flows into and out of the device 200 (properlyinstalled in the model to simulate the installation in a real aorta) areprovided with fluid that models blood, and the flows are controllablyand selectively varied, and the effect on particle migration to theaortic arch, the particles originating upstream of the aorta and/or fromthe perfusion lumen of the device 200 is determined. At the same timethe perfusion flow velocity is preferably kept to below the thresholdvalue V. Thereby, the threshold suction flow rate SFR_(threshold) may beempirically determined.

Alternatively, a computer model simulation of the patient's aorta may becreated, and a suitable computerized flow analysis conducted in thecomputer environment of the fluid flows into and out of the aorticdevice (that is also modeled in the computer simulation), in a computermodel similar to the physical model, mutatis mutandis.

In any case, in at least one embodiment of the standard EROM mode, thesuction flow rate SFR is set well above the threshold suction flow rateSFR_(threshold), at or close to the maximum suction flow rate SFR_(max),and concurrently perfusion is provided at the maximum target perfusionrate TFR_(max), so that the full corresponding maximum excess perfusionflow rate ΔFR_(max) is effectively used for the removal or potentialremoval of embolic emboli from the ascending aorta, while sufficientperfusion is provided at the aforesaid nominal perfusion flow rate NFRfor the needs of the patient, and while maintaining the target perfusionflow rate flowing at flow velocities below the threshold velocity V.

The EROM mode can be used whenever necessary or desired, for example inthe following situations:

-   -   (a) Prior to clamping or occluding the aorta, in anticipation of        and to collect possible embolic debris that may be formed        thereafter.    -   (b) After clamping or occluding the aorta, to collect possible        embolic debris that may be formed as a result thereof    -   (c) After unclamping or removing the occlusion in the aorta, to        collect possible embolic debris that may be formed as a result        thereof    -   (d) Whenever there is a suspicion that embolic debris may be        found in the ascending aorta, or where such embolic debris is        detected.    -   (e) Throughout the cardiac procedure, whenever there is a need        to provide artificial perfusion to the body circulation system.

Between (b) and (c), i.e., after it is considered that any possibleembolic debris has been diverted and removed via the system 100, butbefore it is desired to unclamp or remove the occlusion in the aorta, itis possible to change operating mode from EROM mode to NPOM mode tocontinue providing nominal perfusion to the body circulating system.This switchover in operating modes only requires the suction flow rateSFR to be gradually decreased to zero, while concurrently decreasing thetarget perfusion rate TFR to the nominal perfusion flow rate NFR.

Conversely, just before it is desired to unclamp or remove the occlusionin the aorta, it is possible to change operating mode back to EROM modefrom NPOM mode to begin again suctioning, with a suction flow rateincreasing from zero to the required value, and the target perfusionflow rate TFR similarly increasing, to provide sufficient flow for therecirculation field and to concurrently continue providing nominalperfusion to the body circulating system.

If after (c) there is still suspicion or evidence of embolic debris inthe ascending aorta, the EROM mode can be continued further until allthe embolic debris is removed, prior to starting the heart again, afterwhich if there is no further embolic debris the system 100 can switch tooperating in NPOM mode, and then reduce the actual perfusion rate tozero as the heart takes over the function of providing oxygenated bloodto the body.

Alternatively, it is possible to continue operating in EROM mode evenonce the heart starts again, to eliminate embolic debris that originatesupstream of the aorta. In particular, the system may be operated in suchcircumstances in de-airing mode (DAM), to remove embolic debris in theform of air bubbles. In fact, in such a DAM mode, and when the heart isoperating and providing part or all of the nominal perfusion, the systemmay be configured for providing a suction flow rate that is higher thanrequired in other operating modes.

Referring to (e) above, it may be desired to use EROM mode throughoutthe cardiac procedure, whenever there is a need to provide artificialperfusion to the body circulation system, for example when there is arisk of embolic debris being generated by the extra-corporealcirculation system and introduced into the patient via the perfusionlumen. Thus EROM may completely replace NPOM mode, and is usedcontinuously until the end of the procedure.

Thus, it is evident that the system 100 may be used in EROM modecontinuously, for example from just before it is desired to clamp orprovide the occlusion in the aorta, or even as soon as the device 200 isinstalled, to after the aorta is unclamped or the occlusion removedtherefrom. In such continuous EROM mode, the suction flow rate and thetarget flow rate may be set at a desired preset level, or may be varied,but always maintaining a suitable suction flow and a suitable excessperfusion flow.

It is also evident that the system 100 may be used in an intermittentmanner, in which high target perfusion flow rates TFR and high suctionflow rates SFR are provided when there is danger or risk of embolicdebris, for example during clamping and unclamping of the aorta, andreducing these flow rates to provide zero suction flow rate or low flowrates at other times.

In at least some alternative variations of this embodiment a suitablesensor system may be provided to detect the presence of embolic debrisin the ascending aorta, for example, and for automatically switching thesystem to EROM mode (or possibly automatically increasing further thetarget perfusion flow rates TFR and the suction flow rate SFR, ifalready in EROM mode) when embolic debris is detected. Such a sensor maybe based on Transcranial Doppler technology (referred to in the art asTCD), for example.

Once the heart has fully taken over providing perfusion for the body,the device 200 may be removed, for example in a manner usedconventionally for removing conventional aortic cannulation devices.

It is to be noted that in the absence of contact between the distalportion 201 and the walls 10 of the aorta (other than due to penetrationof the distal portion 201 into the aorta), operation of the system 100or stopping operation of the system 100 at least according to thisembodiment does not per se result in the significant or actual creationof new embolic debris.

An alternative variation of the first embodiment is illustrated in FIG.3( a), in which the device 200 is further modified to include anadditional suction inlet port in the form of an air bubble suction inlet262 that is particularly configured for removing embolic emboli in theform of air bubbles that may be released into the aorta when the aortais unclamped, for example, and thus the arterial device 200 of FIG. 3(a) may be operated as a de-airing device. As may be seen, the air bubblesuction inlet 262 is in communication with the suction lumen 220, and islocated in the distal portion 201 at a location that, in operation ofthe device 200, is close to the inner wall of the aorta 2, preferably ata gravitationally high point in the aortic walls, facilitating migrationof air bubbles thereto for subsequent removal thereof.

An alternative variation of the first embodiment is illustrated in FIG.8, in which the device 200 is further modified to include a selectivelyenlargable device 400 on the external wall 238 of the distal portion201. The enlargeable device 400 in this embodiment comprises aninflatable annular balloon member 410 than may be selectively inflatedfrom a deflated condition, in which the balloon member 410 is close tothe external wall 238, to an inflated condition, illustrated in FIG. 8,in which the balloon member 410 partially obstructs the cross-section ofthe ascending aorta, but still allows for significant fluidcommunication between the inlet suction port 250 and the perfusionoutlet port 250. In particular, the balloon member 410 does not abut orengage with the aortic walls 10, and preferably does not come in contactthe aortic walls 10, in use of the device and when the balloon member410 is in the inflated condition. Use of this embodiment in NPOM mode issimilar to that described herein for the first embodiment, mutatismutandis, and in this mode the balloon member may be inflated ordeflated. Similarly, use of this embodiment in EROM mode is similar tothat described herein for the first embodiment, mutatis mutandis, and inthis mode the balloon member may also be inflated or deflated, thoughwhen inflated, it may operate more efficiently in removing embolicdebris even where the suction flow rate is lower than the aforesaidthreshold suction flow rate SFR_(threshold).

Another alternative variation of the first embodiment is illustrated inFIG. 9, in which the distal portion, designated 201′, is similar to thedistal portion 201 disclosed for the first embodiment, mutatis mutandis,with some differences. These differences include:

-   -   in distal portion 201′ of the embodiment of FIG. 9, the distal        end 204′ of the device now extends into the aortic arch 3;    -   distal portion 201′ includes a plurality of perfusion outlet        ports 240′ rather than the single perfusion outlet port 240 of        the first embodiment;    -   distal portion 201′ includes a plurality of suction inlet ports        250′ rather than the single suction inlet port 250 of the first        embodiment illustrated in FIG. 3, and thus may also include a        de-airing suction port similar to that illustrated for        embodiment of FIG. 3 a.

Further, at least one or more perfusion outlet ports 240′, designated240 a′ are located at a position to be within the ascending aorta 2 whenthe aortic device is installed therein, similar to the position of thesingle perfusion outlet port 240 of the first embodiment, and have acombined exit flow area of A_(a). Another group of one or more perfusionoutlet ports 240′, designated 240 b′ are located at a position to bewithin the aortic arch 3, close to the upstream end 3U thereof, when thearterial device is installed therein, and have a combined exit flow areaof A_(b). Another group of one or more perfusion outlet ports 240′,designated 240 c′ are located at a position to be within the aorticarch, further downstream of perfusion outlet ports 240 b′, and have acombined exit flow area of A_(c). Finally, the distal end 204′ comprisesanother outlet port 240′, designated 240 d′, and having an exit flowarea of A_(d). (Optionally, further perfusion outlet ports may beprovided at different locations on the distal end 201′.)

The combined exit flow areas of all the perfusion outlet ports 240′ issuch as to provide the desired target perfusion flow rate PFR, whilemaintaining the exit velocity below the threshold velocity V.Furthermore, the relative sizes exit flow area of A_(a), A_(b), A_(c)and A_(d) can be set so that the desired flow at the nominal perfusionflow rate NPR is provided via perfusion outlet ports 240 c′ andperfusion outlet ports 240 d′, for example, while the excess perfusionflow at excess perfusion flow rate ΔFR, or at least the proportion P ofthe target perfusion flow rate TFR for matching the suction flow rateSFR, is provided via perfusion outlet ports 240 a′ and perfusion outletports 240 b′. Alternatively, the perfusion flow from the perfusionoutlet ports 240 b′ may be used for the nominal perfusion flow rate NPRinstead of for the excess perfusion flow rate ΔFR.

Operation of the embodiment of FIG. 9 is similar to that disclosedherein for the first embodiment, mutatis mutandis.

In yet other alternative variations of the first embodiment or of theabove variations thereof, the arterial device may comprise a perfusionlumen arrangement having a plurality of perfusion lumens, each in fluidcommunication with one or more suitable perfusion sources, and each oneproviding perfusion flow via the same perfusion outlet port or via aplurality of perfusion outlet ports, and/or, the arterial device maycomprise a suction lumen arrangement having a plurality of suctionlumens, each in fluid communication with one or more suitable suctionsources, and each one providing suction flow via the same suction inletport or via a plurality of suction inlet ports.

A feature of the first embodiment and at least some alternativevariations thereof is that a single entry point is required in theaorta, in particular the ascending aorta, for providing the dualfunctions of providing perfusion to the body circulation system and forremoving embolic debris (and optionally also de-airing), andfurthermore, the same arterial device may be used for providingperfusion where it is not desired to operate the embolic debris removalfunctionality of the arterial device.

The first embodiment, or at least some alternative variations thereof,may be operated according to one or more of the following operatingparameters:

-   -   wherein said nominal perfusion flow rate is in the range between        about 3 liters per minute to about 5 liters per minute;    -   wherein said target flow rate is in the range between about 3.3        liters per minute to about 7.5 liters per minute;    -   wherein said excess perfusion flow rate is in the range between        about 0.3 liters per minute to about 2.5 liters per minute;    -   wherein said suction flow rate is greater than 0.5 liters per        minute;    -   wherein said suction flow rate is greater than 0.75 liters per        minute;    -   wherein said suction flow rate is greater than 1 liter per        minute;    -   wherein said suction flow rate is greater than 1.25 liters per        minute;    -   wherein said suction flow rate is in the range between about 0.5        liters per minute to about 2.0 liters per minute;    -   wherein said suction flow rate is in the range between about 0.5        liters per minute to about 2.5 liters per minute;    -   wherein said suction flow rate is in the range between about        0.75 liters per minute to about 2.5 liters per minute.

Referring to FIGS. 10 and 11, an arterial system according to a secondembodiment of the invention, designated herein with the referencenumeral 500, comprises all the elements and features of the systemaccording to the first embodiment and/or alternative variations thereofand may be operated in a similar manner thereto and with similaroperating parameters, mutatis mutandis, with a number of differences, asfollows. In particular, arterial system 700 comprises an arterial device500 (also referred to interchangeably herein as an aortic device), andcontroller 300. Controller 300 is as disclosed for the first embodiment,mutatis mutandis, and is operatively connected to, and selectivelycontrols, pump 325 and suction source 345, also as disclosed for thefirst embodiment, mutatis mutandis.

Arterial device 700 is in the form of an aortic catheter, in particularan intra-aortic double-lumen catheter, configured for being insertedinto the aorta 1, in particular the ascending aorta 2, during operationof the system 100, via a suitable insertion point 799, well downstreamof the aortic arch 3. In this embodiment, the insertion point 799 is inthe femoral artery of the patient, but in alternative variations of thisembodiment, the insertion point may instead be one of the iliac arteries8, or a suitable location in the abdominal portion of the descendingaorta 4, or indeed any other suitable point along the descending aorta.

Device 700 comprises two internal lumens—a perfusion lumen 710 and anaspiration or suction lumen 720, and comprises a generally tubular outerwall 730 concentric with a generally tubular inner wall 740. Perfusionlumen 710 is defined in the annular space between the inner wall 735 andthe outer wall 730, while suction lumen 720 is defined by the spaceenclosed by the inner wall 735. At a distal end 704 of the device 700the suction lumen 720 opens to a suction inlet port 750, while theannular space between the inner wall 735 and the outer wall 730 isclosed by end wall 760, indicating the distal end of the perfusion lumen710. Thus, suction inlet port 750 is distal end of the device 700 and inuse the suction inlet port 750 faces in a general upstream direction Sof the aorta.

The device 700 comprises a distal portion 701 configured for beingaccommodated within the aorta, so that in use of the system 500 thedistal end 704 is located within the ascending aorta 2 of the patient. Aproximal end 705 of the distal portion 701 is located at the entry point799 in use of the system 500.

The proximal end 705 of the device 700 is contiguous with a proximalportion 702 of the device, and the proximal portion 702 comprises aperfusion inlet port 745 and a suction outlet port 755. The proximalportion 702 thus projects out of the entry point 799 of the body andinterfaces with other components of the system 500. The proximal portion702 is configured for remaining outside of the entry point 799concurrently when the distal portion 701 is installed in the aorta.

The distal portion 701 further comprises a plurality of perfusion outletports, collectively designated 740, laterally or radially disposed onthe outer wall 730. One or more perfusion outlet ports 740 are locatedon the device 700 to be distally of the aortic arch 3, i.e., in theascending aorta 2, in operation of the device 700, and are alsodesignated herein as distal perfusion outlet ports 740 d. Additional oneor more outlet ports 740 are located proximally of the distal perfusionoutlet ports 740 d are designated herein as proximal perfusion outletports 740 p. In the illustrated embodiment, the proximal perfusionoutlet ports 740 p are located on the device 700 to be in or justdownstream of the aortic arch 3, in the upper portion of the thoracicdescending aorta, in operation of the system 500. However, inalternative variations of this embodiment, the proximal perfusion outletports 740 p may instead be located on the device 700 to be within theaortic arch 3, or in the ascending aorta 2 but downstream of the suctioninlet port 750, or in the abdominal portion of the descending aorta 4,in operation of the device. In yet other alternative variations of thisembodiment, the proximal perfusion outlet ports 740 p are integral withthe distal perfusion outlet ports 740 d.

Returning to the second embodiment illustrated in FIGS. 10 and 11, theperfusion lumen 710 thus extends contiguously between the perfusioninlet port 745 and the perfusion outlet ports 740, and provides fluidcommunication therebetween. Similarly, the suction lumen 720 thusextends contiguously from the suction outlet port 755 to the suctioninlet port 750, and provides fluid communication therebetween.Furthermore, the perfusion outlet ports 740 are downstream of thesuction inlet port 750 (in terms of the antegrade aorta flow).

Device 700 is configured for operating within an artery, in particularthe aorta 1, more in particular the ascending aorta 2, in a manner toprovide fluid communication between the perfusion outlet ports 740 andthe suction inlet port 750 within the artery, aorta or ascending aorta,respectively, via the outside 738 of the distal portion 701 of thedevice 700.

Thus, distal portion 701 has an outside 738 (also referred tointerchangeably herein as an outer surface of the distal portion 701)that in use of the device 700 does not occlude or otherwise obstruct theartery, aorta or ascending aorta in which the distal portion 701 isinserted, in particular within a region of the corresponding bloodvessel between the location of the suction inlet port 750 and thelocation of the perfusion outlet ports 740. Furthermore, the device 700,and in particular the distal portion 701, has an absence of anyocclusion arrangement that is otherwise configured for occluding ofobstructing the artery, in particular the aorta, more particularly theascending aorta during use of the device such as to prevent such fluidcommunication between the perfusion outlet ports 740 and the suctioninlet port 750 via the outside 738.

In alternative variations of this embodiment in which the distal portionmay be configured with one or more occlusion devices (for exampleinflatable balloons) positioned at a location inbetween the location ofthe suction inlet port and the location of the perfusion outlet ports,and having an inoperative state in which the occlusion device does notocclude the blood vessel in which the device is installed, and anoperative state in which the occlusion device occludes or blocks theblood vessel, such a device is operated with the occlusion device in theaforementioned inoperative state or at least not in the aforementionedoperative state.

At the distal end of the proximal portion 702 there is provided a collar739. In use of the device 700, collar 739 abuts against an outer surfaceof the blood vessel in which the device is inserted, via the entry point799, and may be used to limit the penetration of the device 700 into theaorta so that in this position the distal end 704 is at the desiredlocation within the ascending aorta. Furthermore, the collar 739 mayassist in affixing the device 700 to the body.

The device 700 may be formed from substantially rigid and/or semi-rigidand medically compatible materials, including, for example includingmedically suitable plastics, silicon, rubber or composite materials thatare known in the art for use in aortic catheter devices. The device 700may thus be configured as disposable device, being made from disposablematerials and disposed of after use with a patient. Alternatively thedevice may be configured as an autoclavable or otherwise sterilizableand non-disposable device, and formed from suitable materials.

In a similar manner to that disclosed for the first embodiment, mutatismutandis, perfusion lumen 710 is configured for providing at least anominal perfusion flow, i.e., having a nominal perfusion blood flow rateNFR, provided at a nominal flow velocity NFV that is below a thresholdvalue V, and in particular, the perfusion lumen 710 is configured forproviding a target perfusion flow having a target perfusion flow rateTFR that is significantly greater than the aforesaid nominal perfusionflow rate NFR by a factor ΔFR, referred to herein the excess perfusionflow rate. Furthermore, the perfusion lumen 710 is configured forproviding a maximum target perfusion flow having a corresponding maximumtarget perfusion flow rate TFR_(max) that is greater than the aforesaidnominal perfusion flow rate NFR by a corresponding maximum excessperfusion flow rate ΔFR_(max). Thus, in the second embodiment, theperfusion lumen 710 also comprises a minimum cross-sectional flow areathat is correspondingly larger than would be otherwise be required forproviding only the nominal perfusion flow rate NFR, in order to enableflow rates of up to the aforesaid maximum target perfusion flow rateTFR_(max), but still at the flow velocities which are still below theaforesaid threshold value V.

In a similar manner to that disclosed for the first embodiment, mutatismutandis, suction lumen 720 has a minimum cross-sectional flow area thatis smaller than the minimum cross-sectional flow area of the perfusionlumen 710, and in the second embodiment is configured for providing asuction flow rate SFR that can be varied from zero to a maximum suctionflow rate SFR_(max) that is generally similar to the correspondingmaximum excess perfusion flow rate ΔFR_(max).

The perfusion inlet port 745 is configured for being connected to, andthus for receiving oxygenated blood from, a suitable perfusion source320, as disclosed for the first embodiment, mutatis mutandis. A suitablepump 325, as disclosed for the first embodiment, mutatis mutandis, pumpsoxygenated blood from the perfusion source 320 to the device 700, and isconfigured for providing a controllable perfusion flow rate at least upto the maximum target perfusion flow rate TFR_(max) for the particularpatient being treated by system 100, and is variably controllable toprovide perfusion flow rates from nominally zero to at least up to themaximum target perfusion flow rate TFR_(max).

Thus, as with the first embodiment, mutatis mutandis, the pump 325 isoperatively connected to, and is controlled by, controller 300, andcontroller 300 is configured for controlling the pump 325 to provide anydesired perfusion flow rate in the range between zero and at least themaximum target perfusion flow rate TFR_(max).

The suction outlet port 755 is configured for being connected to, andthus for returning blood to, a suitable suction source 345, as disclosedfor the first embodiment, mutatis mutandis, and the suction source 345is controllable and is operatively connected to, and is controlled by,controller 300.

Thus, as with the first embodiment, mutatis mutandis, the suction source345 is configured for providing a variably controllable suction flowrate from nominally zero to at least the maximum suction flow rateSFR_(max), and the controller 300 is configured for controlling thesuction source 345 to provide any desired suction flow rate in the rangebetween zero and at least the maximum suction flow rate SFR_(max).

In at least some operational modes of the system 500, the suction source345 sucks or aspirates blood via the device 700 and into a suitablereceiving volume 340. As with the first embodiment, mutatis mutandis, inalternative variations of the second embodiment as well, the bloodcollected at receiving volume 340 may be subsequently suitably processedto remove embolic debris and may be then supplied to the perfusionsource 320 to provide a closed system.

Thus, in operation the system 500 comprises arterial device 200 andextra-corporeal circulation system 690, which comprises controller 300,pump 325, perfusion source 320 and suction source 345, and optionallyalso receiving volume 340. Extra-corporeal circulation system 690 isthus substantially similar or identical to extra-corporeal system 290 ofthe first embodiment.

In operation of the system 500, the distal portion 701 is inserted intothe aorta 2 via the aforementioned entry point 799 and navigatedupstream until the distal end 704 is located within the ascending aorta2. Surgical procedures for inserting intra-aortic catheters from anentry point in the descending aorta or further downstream such as theiliac arteries or femoral arteries are well known in the art.

System 500 can be operated in a manner similar to that described for thefirst embodiment, mutatis mutandis, and thus may be operated in thenominal perfusion operating mode (NPOM), in which the system 500operates to provide oxygenated blood at least at the nominal perfusionflow rate NFR to the body circulation system, and/or in the embolicdebris removal operating mode (EROM), in which the system 500 operatesto provide oxygenated blood at least at the nominal perfusion flow rateNFR to the body circulation system, while concurrently removing embolicdebris and preventing the same from flowing to the aortic arch 3, asdisclosed above, mutatis mutandis.

Other than the difference in the method of introducing the aortic deviceinto the aorta, the main difference in operation of the system 500 ofthe second embodiment, as compared to system 100 of the firstembodiment, is that in the second embodiment the perfusion flow providedvia the perfusion lumen 710 exists the perfusion lumen at the pluralityof perfusion outlet ports 740. In NPOM mode perfusion blood is providedat the nominal perfusion flow rate NFR via the distal perfusion outletports 740 d and the proximal perfusion outlet ports 740 p, and the flowfrom the latter may be antegrade and/or retrograde, according to therelative sizes of the distal perfusion outlet ports 740 d and theproximal perfusion outlet ports 740 p and their locations in the aorta,so that the arteries that branch off from the aortic arch may receiveblood from the distal perfusion outlet ports 740 d and possibly alsofrom the proximal perfusion outlet ports 740 p. In EROM mode, therelative sizes of the distal perfusion outlet ports 740 d and theproximal perfusion outlet ports 740 p and their locations in the aortamay be such that the proportion P of the target perfusion flow rate TFRthat sustains the suction flow rate SFR may be provided solely via thedistal perfusion outlet ports 740 d, while the remainder of the targetperfusion to the body circulation system may be provided solely via theproximal perfusion outlet ports 740 p or may be contributed to also viathe distal perfusion outlet ports 74.

In an alternative variation of the second embodiment, illustrated inFIG. 12, the distal end 704′ of the device 700 comprises a closed endwall 739 and a tubular wall extension 737 extending distally from outerwall 730 distally of annular wall 760, defining a distal portion of thesuction lumen 720. Distal end 704′ comprises a plurality of inletsuction ports 750′, instead of the single inlet suction port 750 of thesecond embodiment, and are laterally or radially disposed on the tubularwall extension 737. In this embodiment the suction lumen 720 thusextends contiguously from the suction outlet port 755 to the suctioninlet ports 750′, and provides fluid communication therebetween.

Installation and operation of the embodiment illustrated in FIG. 12 issimilar to that disclosed for the second embodiment illustrated in FIGS.10 and 11, mutatis mutandis.

Referring to FIG. 13, an arterial system according to a third embodimentof the invention, designated herein with the reference numeral 800,comprises all the elements and features of the system according to thefirst embodiment and/or alternative variations thereof and may beoperated in a similar manner thereto and with similar operatingparameters, mutatis mutandis, with a number of differences, as follows.In particular, arterial system 800 comprises an arterial fluid exchangesystem 810, and controller 300′.

In the third embodiment, the function of providing the body with thenominal perfusion flow rate NFR and the function of causing embolicdebris to be removed (e.g., by providing a recirculation flow field) areseparately performed by two separate arterial devices. Thus, thearterial fluid exchange system 810 comprises an embolic debris removaldevice 820 and an arterial perfusion cannula 830. Controller 300′ issimilar to the controller 300 of the first embodiment, mutatis mutandis,but is configured for selectively controlling the fluid flows throughembolic debris removal device 820 and arterial perfusion cannula 830.

Arterial perfusion cannula 830 is configured for providing perfusion tothe body circulation system, and thus provide the nominal perfusion flowrate NFR. The arterial perfusion cannula 830 is in fluid communicationwith a suitable perfusion source 320 a via pump 325 a, similar to theperfusion source 320 and pump 320 of the first embodiment, mutatesmutandis. The perfusion cannula 830 thus has a lumen that is of asuitable size and form to enable the required nominal perfusion flowrate NFR to be supplied to the body circulation system, and controller300′ controls operation of the pump 320 a, and thus of the nominalperfusion flow rate NFR.

In this embodiment, the arterial perfusion cannula 830 is inserted intothe aorta in a manner similar to conventional aortic cannulation devicesused for perfusion, and is located downstream of the embolic debrisremoval device 820.

The embolic debris removal device 820 of this embodiment is similar inform to the aortic device 500 of the first embodiment, and alternativevariations thereof, mutatis mutandis, but with some differences as willbecome clearer herein. The embolic debris removal device 820 thuscomprises a distal portion that is inserted into the ascending aorta 2,and comprises a perfusion lumen 210 a and a suction lumen 220 a. Theperfusion lumen 210 a is in fluid communication with a second perfusionsource 320 b, via pump 325 b, similar to the first embodiment, mutatismutandis. The suction lumen 220 a is in fluid communication with asuction source such as pump 345 and optionally reservoir 340, as in thefirst embodiment, mutatis mutandis, and may in all respects besubstantially identical to the corresponding components of the firstembodiment, mutatis mutandis. The pumps 345 and 325 b are operativelyconnected to, and are electively controlled by, controller 300′.

In alternative variations of this embodiment, a single pump may be usedto carry out the functions of pumps 345 and 325 b.

In alternative variations of this embodiment, first perfusion source 320a and second perfusion source 320 b are integrated into a singleperfusion source.

Perfusion lumen 210 a is similar to the perfusion lumen 210 of the firstembodiment, mutatis mutandis, but differs therefrom in that in the thirdembodiment, the perfusion lumen 210 a is configured for providing onlythe excess perfusion flow ΔFR into the aorta, rather than the fulltarget perfusion flow rate TFR. Thus, the internal cross section of theperfusion lumen 210 a may be correspondingly smaller with respect to theperfusion lumen of the first embodiment, mutatis mutandis.

Thus, while arterial fluid exchange system 810 provides the target flowrate TFR into the aorta, the arterial perfusion cannula 830 isconfigured for providing the nominal perfusion flow rate NFR while theembolic debris removal device 820 provides the remainder of the targetperfusion flow rate, i.e., the excess perfusion flow rate ΔFR.

Arterial system 800 thus operates in a similar manner to the arterialsystem 100 of the first embodiment, including operating modes such asthe EROM and the NPOM mode, as disclosed for the first embodiment,mutatis mutandis, with the main differences including that the excessperfusion flow rate ΔFR is also matched at a desired matching level tothe suction flow rate SFR (in a similar manner to that disclosed abovefor the first embodiment, mutatis mutandis), but via the embolic debrisremoval device 820, while the nominal perfusion flow NFR is beingselectively provided by the arterial perfusion cannula 830 independentlythereof. Of course, it is possible to operate the embolic debris removaldevice 820 to provide an excess perfusion flow rate ΔFR that is higherthan the suction flow rate SFR, and thus the excess perfusion flow rateΔFR will also effectively provide perfusion flow to the body circulationsystem, or to provide an excess perfusion flow rate ΔFR that is lessthan the suction flow rate SFR, and concurrently operate the arterialperfusion cannula 830 to provide a perfusion flow rate that is higherthan the nominal perfusion flow rate NPR to compensate.

Without being bound by theory, inventors consider that when the excessperfusion flow rate ΔFR is suitably matched to the suction flow rateSFR, and the suction flow rate SFR is above the threshold valuediscussed above, a substantially self-contained recirculation field maybe set up between the perfusion outlet 832 of the perfusion lumen 210 a,and the suction inlet 834 of the suction lumen 834 of the suction lumen220 a, in a similar manner to that discussed above for the firstembodiment, mutatis mutandis. However, for this to occur, the arterialperfusion cannula 830 is operated to provide a perfusion flow ratesufficient to effectively or actually create a stagnation zone Zinbetween the locations of the arterial perfusion cannula 830 and theembolic debris removal device 820. The recirculation flow fieldgenerated by the embolic debris removal device 820 causes embolic debristhat may be present in the aorta to be diverted to the suction inlet 834and is subsequently removed.

The embolic debris removal device 820 may optionally comprise a flowdiverter 250 facing the perfusion outlet 832 and spaced therefrom, tofacilitate recirculation of the excess perfusion flow rate ΔFR in aretrograde direction towards the upstream part of the ascending aorta.

A feature of this embodiment or at least one alternative variationthereof is that the perfusion lumen 210 a of the embolic debris removaldevice 820 can be designed to be much smaller than the perfusion lumenof the first embodiment, for example, and thus the overall size ofembolic debris removal device 820 may be reduced as compared to theaortic device of the first embodiment, for example. Alternatively, theperfusion lumen 210 a may be of increased size (for example as in theaortic device of the first embodiment) which effectively reduces theflow velocity at the perfusion outlet 832 for a given excess perfusionflow rate ΔFR.

Another feature of this embodiment or at least one alternative variationthereof is that the excess perfusion rate ΔFR can be fully matched(matching level of 100%) to the suction flow rate SFR in the embolicdebris removal device 820, which is a separate device to the arterialperfusion cannula 830. Thus, since substantially all the excessperfusion rate ΔFR is effectively recirculated within the ascendingaorta and sucked out as the suction flow rate, a perfusion fluid may beused for this that is different from that of the perfusion flow beingprovided by the arterial perfusion cannula 830. For example, a suitablesaline solution or blood plasma may be used as the perfusion fluidprovided to the embolic debris removal device 820 instead of oxygenatedblood, to provide the excess perfusion rate ΔFR, and this issubsequently removed via the suction lumen 220 a together with embolicdebris. A feature of this arrangement is that it is not necessary to useup valuable oxygenated blood for the purpose of removing the embolicemboli. Another feature of this is that flow velocities may be used forthe excess perfusion rate ΔFR can be greater than the threshold velocityreferred to above, since the operating fluid is now saline solution (forexample) and not blood that could otherwise be damaged.

As in the first embodiment or alternative variations thereof, theembolic debris removal device 820 may comprise an air bubble suctioninlet 838 that is particularly configured for removing embolic emboli inthe form of air bubbles that may be released into the aorta when theaorta is unclamped, for example, similar an form and function to the airbubble suction inlet of the first embodiment, mutatis mutandis, and thusthe embolic debris removal device 820 may be operated as a de-airingdevice.

Referring to FIG. 14, an arterial system according to a fourthembodiment of the invention, designated herein with the referencenumeral 900, comprises all the elements and features of the systemaccording to the third embodiment and/or alternative variations thereofand may be operated in a similar manner thereto and with similaroperating parameters, mutatis mutandis, with a number of differences, asfollows. In particular, arterial system 800 comprises an arterial fluidexchange system 840, and controller 300′.

As with the third embodiment, in the fourth embodiment, the function ofproviding the body with the nominal perfusion flow rate NFR and thefunction of providing a recirculation flow field to cause embolic debristo be removed are separated and performed by two separate devices. Thus,the arterial fluid exchange system 840 comprises the embolic debrisremoval device 820, as disclosed for the third embodiment or alternativevariations thereof, mutatis mutandis, and an arterial perfusion catheter860. Controller 300′ is as disclosed with respect to the thirdembodiment, mutatis mutandis.

As with the third embodiment, the perfusion lumen 210 a is in fluidcommunication with a second perfusion source 320 b, via pump 325 b, andthe suction lumen 220 a is in fluid communication with a suction sourcesuch as pump 345 and optionally reservoir 340, and the pumps 345 and 325b are operatively connected to, and are selectively controlled by,controller 300′.

Arterial perfusion catheter 860 is configured for providing perfusion tothe body circulation system, and thus for providing the nominalperfusion flow rate NFR. The arterial perfusion catheter 860 is similarin function to the arterial perfusion cannula of the third embodiment,and is in fluid communication with perfusion source 320 a via pump 325a, as disclosed for the third embodiment, mutates mutandis. Theperfusion catheter 860 thus has a lumen that is of a suitable size andform to enable the required nominal perfusion flow rate NFR to besupplied to the body circulation system, and controller 300′ controlsoperation of the pump 320 a, and thus of the nominal perfusion flow rateNFR.

In this embodiment, the arterial perfusion catheter 860 is inserted intothe aorta in a manner similar to conventional aortic catheter devicesused for perfusion, and is located downstream of the embolic debrisremoval device 820. For example, the arterial perfusion catheter 860 maybe inserted into the aorta and navigated into a position in the aorticarch 3, similar to that disclosed herein for the aortic device 700 ofthe second embodiment, mutatis mutandis.

Arterial system 900 thus operates in a similar manner to the arterialsystem 800 of the third embodiment, including operating modes such asthe EROM and the NPOM mode, and also for de-airing via air bubblesuction inlet 838, as disclosed for the third embodiment, mutatismutandis, with the main differences being that a perfusion catheter isused for providing the nominal flow rate NFR to the body circulation,rather than a perfusion cannula. Accordingly, the arterial system 900shares many of the features of the arterial system of the thirdembodiment, and has at least another feature in that it avoids having toprovide two entry points at or close to the ascending aorta.

In the method claims that follow, alphanumeric characters and Romannumerals used to designate claim steps are provided for convenience onlyand do not imply any particular order of performing the steps.

Finally, it should be noted that the word “comprising” as usedthroughout the appended claims is to be interpreted to mean “includingbut not limited to”.

While there has been shown and disclosed example embodiments inaccordance with the invention, it will be appreciated that many changesmay be made therein without departing from the spirit of the invention.

The invention claimed is:
 1. An arterial system, comprising: an arterialflow exchange system; and a controller, for use with a patient having anaorta and a body blood circulation system, wherein: said arterial flowexchange system comprises a distal portion arrangement configured forbeing accommodated in the aorta of the patient in use of the arterialflow exchange system, said distal portion arrangement comprising: aperfusion lumen arrangement having at least one perfusion outlet andconnectable to at least one perfusion source, said perfusion lumenarrangement being configured for providing therethrough a targetperfusion flow into the aorta having a target perfusion flow rate thatis greater than a nominal perfusion flow rate by an excess perfusionflow rate, wherein said nominal perfusion flow is sufficient forproviding adequate fluid flow to the body blood circulation system ofthe patient; and a suction lumen arrangement having at least one suctioninlet and connectable to a suction source, said suction lumenarrangement being configured for providing a suction flow out of theaorta, said suction flow having a suction flow rate; said distal portionbeing configured for providing fluid communication between at least onesaid perfusion outlet and at least one said suction inlet within theaorta via an outside of said distal portion, in use of the arterialsystem; said controller being configured, in use of the arterial system,for: selectively controllably providing a target perfusion flow into theaorta at said target perfusion flow rate; selectively controllablyproviding a suction flow out of the aorta at said suction flow rate; andselectively controlling said target perfusion flow rate and said suctionflow rate concurrently to cause embolic debris that may be present inthe aorta to be diverted to said at least one suction inlet.
 2. Thesystem according to claim 1, wherein said suction flow rate is aproportion of a said nominal perfusion flow rate, wherein saidproportion is not less than about 10% of said nominal perfusion flowrate.
 3. The system according to claim 1, wherein said arterial flowexchange system is embodied in an arterial device, and said distalportion arrangement constitutes a distal portion of said arterial deviceand is configured for being accommodated into the aorta, wherein saidarterial device is in the form of an aortic cannula, wherein said distalportion is configured for being introduced into the aorta via a wall ofthe ascending aorta.
 4. The system according to claim 3, wherein saidperfusion lumen arrangement comprises a first lumen, wherein saidsuction lumen arrangement comprises a second lumen, and wherein saidfirst lumen and said second lumen are integrally formed in said distalportion, wherein said first lumen has a first flow cross-section andsaid second lumen has a second flow cross-section, wherein a crosssection ratio between said first flow cross-section and said second flowcross-section is between about 1.10 and about 10.0.
 5. The systemaccording to claim 1, wherein said arterial flow exchange system isembodied in an arterial device, and wherein said arterial device is inthe form of an aortic catheter, wherein said distal portion isconfigured for being introduced into the aorta via an entry point at alocation downstream of the descending aorta, the distal portion beingfurther configured for being navigated upstream to the ascending aorta.6. The system according to claim 1, wherein said target flow rate is inthe range between about 3.3 liters per minute to about 7.5 liters perminute and wherein said suction flow rate is greater than 0.5 liters perminute.
 7. The system according to claim 1, wherein at least a portionof said excess perfusion flow rate is in a retrograde direction towardsan upstream part of the aorta.
 8. The system according to claim 1,wherein said excess perfusion flow rate is in a retrograde directiontowards an upstream part of the aorta.
 9. An arterial device, for usewith a patient having an aorta and a body blood circulation system, thearterial device comprising: a distal portion arrangement configured forbeing accommodated in the aorta of the patient in use of the arterialdevice, said distal portion arrangement comprising: a perfusion lumenarrangement having at least one perfusion outlet and connectable to atleast one perfusion source, said perfusion lumen arrangement beingconfigured for providing therethrough a target perfusion flow into theaorta having a target perfusion flow rate that is greater than a nominalperfusion flow rate by an excess perfusion flow rate, wherein saidnominal perfusion flow is sufficient for providing adequate fluid flowto the body blood circulation system of the patient; and a suction lumenarrangement having at least one suction inlet and connectable to asuction source, said suction lumen arrangement being configured forproviding a suction flow out of the aorta, said suction flow having asuction flow rate; said distal portion being configured for providingfluid communication between at least one said perfusion outlet and atleast one said suction inlet within the aorta via an outside of saiddistal portion, in use of the arterial device; wherein the arterialdevice is configured for enabling said target perfusion flow rate andsaid suction flow rate to be concurrently and selectively controlled tocause embolic debris that may be present in the aorta to be diverted tosaid at least one suction inlet.
 10. The arterial device according toclaim 9, wherein said arterial device is in the form of an aorticcannula, wherein said distal portion is configured for being introducedinto the aorta via a wall of the ascending aorta and comprises a curvedportion and a distal end, wherein said distal end comprises said atleast one perfusion outlet, and wherein said curved portion comprisessaid at least one suction inlet.
 11. The arterial device according toclaim 10, wherein said perfusion lumen arrangement comprises a firstlumen, wherein said suction lumen arrangement comprises a second lumen,and wherein said first lumen and said second lumen are integrally formedin said distal portion, wherein said first lumen has a first flowcross-section and said second lumen has a second flow cross-section,wherein a cross section ratio between said first flow cross-section andsaid second flow cross-section is not less than about 1.10.
 12. Thearterial device according to claim 11, wherein said cross section ratiois between about 1.10 and about 10.0.
 13. The arterial device accordingto claim 9, wherein said suction flow rate is greater than 0.5 litersper minute.
 14. The arterial device according to claim 9, wherein atleast a portion of said excess perfusion flow rate is in a retrogradedirection towards an upstream part of the aorta.
 15. A method forremoving embolic debris from an aorta of a patient having a body bloodcirculation system, comprising: (a) providing an arterial flow exchangesystem comprising a distal portion arrangement configured for beingaccommodated in the aorta of the patient in use of the arterial flowexchange system, said distal portion arrangement comprising: a perfusionlumen arrangement having at least one perfusion outlet and connectableto at least one perfusion source, said perfusion lumen arrangement beingconfigured for providing therethrough a target perfusion flow into theaorta having a target perfusion flow rate that is greater than a nominalperfusion flow rate by an excess perfusion flow rate, wherein saidnominal perfusion flow is sufficient for providing adequate fluid flowto the body blood circulation system of the patient; and a suction lumenarrangement having at least one suction inlet and connectable to asuction source, said suction lumen arrangement being configured forproviding a suction flow out of the aorta, said suction flow having asuction flow rate; said distal portion being configured for providingfluid communication between at least one said perfusion outlet and atleast one said suction inlet within the aorta via an outside of saiddistal portion, in use of the arterial flow exchange system; (b)accommodating said distal portion arrangement in the aorta of thepatient so that at least one said suction inlet port is accommodated inthe ascending aorta of the patient; (c) controllably providing a targetperfusion flow into the aorta at said target perfusion flow rate; (d)controllably providing a suction flow out of the aorta at said suctionflow rate; and (e) selectively controlling said target perfusion flowrate and said suction flow rate to cause embolic debris that may bepresent in the aorta to be diverted to said at least one suction inlet.16. The method according to claim 15, wherein step (e) comprises atleast one of: selectively controlling said target perfusion flow rateand said suction flow rate to establish a recirculation flowfieldbetween at least one said perfusion outlet and at least one said suctioninlet within the aorta to cause the embolic debris that may be presentin the aorta to be diverted to the respective at least one said suctioninlet selectively matching said suction flow rate with said excessperfusion flow rate according to a desired matching level, defined as apercentage of said suction flow rate with respect to said excessperfusion flow rate, wherein said matching level is about 100%.
 17. Themethod according to claim 15, wherein said suction flow rate is aproportion of a said nominal perfusion flow rate, wherein saidproportion is not less than about 10% of said nominal perfusion flowrate.
 18. The method according to claim 15, wherein said arterial flowexchange system is embodied in an arterial device, and said distalportion arrangement constitutes a distal portion of said arterial deviceand configured for being accommodated into the aorta, wherein saidarterial device is in the form of an aortic cannula, and wherein in step(b) said distal portion is introduced into the aorta via a wall of theascending aorta.
 19. The method according to claim 15, wherein saidnominal perfusion flow rate is in the range between about 3 liters perminute to about 5 liters per minute, wherein said target flow rate is inthe range between about 3.3 liters per minute to about 7.5 liters perminute, and wherein said suction flow rate is in the range between about0.5 liters per minute to about 2.0 liters per minute.
 20. The methodaccording to claim 15, wherein at least a portion of said excessperfusion flow rate is in a retrograde direction towards an upstreampart of the aorta.
 21. The method according to claim 15, wherein saidexcess perfusion flow rate is in a retrograde direction towards anupstream part of the aorta.
 22. An arterial device, for use with apatient having an aorta and a body blood circulation system, thearterial device comprising: a distal portion arrangement configured forbeing accommodated in the aorta of the patient in use of the system,said distal portion arrangement comprising: a perfusion lumenarrangement having at least one perfusion outlet and connectable to atleast one perfusion source, wherein said perfusion lumen arrangement isconfigured for providing therethrough a perfusion flow having aperfusion flow rate; and a suction lumen arrangement having at least onesuction inlet and connectable to a suction source, said suction lumenarrangement being configured for providing a suction flow out of theaorta, said suction flow having a suction flow rate; wherein saidsuction flow rate is greater than 0.5 liters per minute.
 23. Thearterial device according to claim 22, wherein at least a portion ofsaid excess perfusion flow rate is in a retrograde direction towards anupstream part of the aorta.
 24. The arterial device according to claim22, wherein said excess perfusion flow rate is in a retrograde directiontowards an upstream part of the aorta.